PETITIONED PUBLIC HEALTH ASSESSMENT
WALLINGFORD, NEW HAVEN COUNTY, CONNECTICUT
In March 1984, citizens of Wallingford, Connecticut contacted the Connecticut Department of Health Services (CDHS) about health problems they were experiencing that they believed were linked to poor air quality. CDHS performed an epidemiologic study and analyzed two sources of data on the symptoms being reported. The U.S. Environmental Protection Agency (EPA) performed several air monitoring studies. That sampling, limited to several short periods, did not identify air contaminants at levels of public health concern. However, the review of toxicologic data indicate that the chemicals in, or that could be in, Wallingford's air, could cause many of the symptoms reported by the citizens, if the concentrations in the air were considerably higher than observed. Relatively large amounts of pollutants are being released from automotive, industrial, and other sources in the Wallingford area. Although the health complaints reported by the residents were not widespread, there is a potential for human exposure of health significance based on the amounts of contaminants, and the presence of conditions that would maximize exposures. The Agency for Toxic Substances and Disease Registry (ATSDR) concludes that the situation in the Town of Wallingford (the Air Quality Petition Site) is an indeterminate public health hazard due to the inadequate amount of data available on the levels of airborne contaminants.
A more thorough characterization of Wallingford air quality should be undertaken. To implement this, a panel of interested and knowledgeable representatives from the Connecticut Departments of Health Services and Environmental Protection, the Town of Wallingford, SPARROW and/or other concerned citizens, the major industries in Wallingford, and the U.S. Environmental Protection Agency should be convened. This panel could help define the scope of such monitoring, and possibly share resources. ATSDR will coordinate the convening of the panel recommended previously.
On December 15, 1987, Dr. Peter D. Galbraith, CDHS, petitioned the ATSDR to assess the environmentally related health complaints of 10-15 families in the Wallingford, Connecticut, area.1 State Representatives Mary G. Fritz (Ninetieth District) and Mary Mushinsky (Eighty-Fifth District), U.S. Representative Bruce A. Morrison (Third District), and U.S. Senator Joseph I. Lieberman submitted co-petitions.2,3,4 In all four petitions, poor air quality was identified as the suspected source of the reported health problems.
Typically, an ATSDR public health assessment evaluates a particular site that has been contaminated with toxic substances and which may serve as a source of exposure to the population in the area. However, the health complaints reported by Wallingford residents are most commonly attributed to air pollution. Consequently, this public health assessment treats the Town of Wallingford as the site. Contamination (pollution) sources from both inside and outside the site boundaries (town limits) and their possible impact on public health are evaluated. Specific health complaints and relevant health outcome data are also analyzed for possible connections to the environment.
Wallingford is an area of 40 square miles5 about 15 miles north of New Haven, Connecticut, and Long Island Sound. The town, which is in the center of the Quinnipiac River Valley, runs mostly north and south, is about two to three miles in width, has ridges about 500 feet above the valley floor (see Figure 1 in Appendix 3), and is mostly covered by hardwood forest. The town, which has a long history of industrialization, is bordered by the Wilbur Cross Parkway (Connecticut Highway 15) on the west and Interstate 91 on the east (see Figure 2 in Appendix 3). The locations of industrial facilities in the Wallingford area are shown in Figure 1. The largest, American Cyanamid (AC), was opened in 1940.
In early 1984, several Wallingford residents began keeping logs of periodic recurrences of sore throats, glandular swelling, gastrointestinal upset and/or cramping in their families. The residents believed that their illnesses were linked to toxic substances being emitted into Wallingford's air by the AC plant and other industrial facilities. In April 1984, CDHS was contacted about the problem. Many of the residents reporting symptoms organized a community action group called Support Preventive Air Regulation Residents of the World (SPARROW).
The reported illnesses were initially investigated as an infectious disease cluster by the Epidemiology Section of CDHS, then followed up as a possible toxic exposure by CDHS's Toxic Hazards Section. That unit suggested that the Wallingford residents continue to keep their logs of symptoms. The logs were reviewed by CDHS along with similar information from a hotline established by the Town of Wallingford.
As part of its investigation of this situation, the U.S. Environmental Protection Agency (EPA) sampled the air in Wallingford for toxic substances in August and September 1984 and again in February 1985. AC's contractor, TRC Environmental Consultants, monitored for toxics on and near the AC facility in Wallingford on several occasions between June and August 1984. In April 1985, EPA conducted a meteorologic evaluation of the situation. These health and environmental data will be discussed in detail later in this document.
CDHS established a mechanism to identify additional health complaints through contact with area physicians. However, active investigation essentially ended in June 1985 because CDHS could neither identify a plausible cause for the reported illnesses nor recommend additional methods of investigation.6 CDHS did continue to take complaints from citizens and to address specific problems such as the sewer gas concern described subsequently.
SPARROW continued to report that residents, especially children, were experiencing symptoms. In 1987 the group suggested sewer gas as another possible source of the problem. The continued concerns led to CDHS' petition to ATSDR in 1987.
Several site visits have been made relating to Wallingford. In October 1987, Ms. Marilyn Disirio of ATSDR toured Wallingford and met with staff from CDHS, the Connecticut Department of Environmental Protection (CDEP), and the Town of Wallingford; members of SPARROW; and two Connecticut State Representatives. Dr. John Abraham of ATSDR and Ms. Marilyn Disirio toured Wallingford and met with CDHS, SPARROW, AC, and the Connecticut State Representatives during four separate site visits in 1989.7 They solicited public concerns at a meeting in Wallingford on July 6, 1989. During a site visit conducted September 4-7, 1990, Dr. John Crellin and Harvey Rogers of ATSDR met with staff from CDHS, CDEP, AC, and the Town of Wallingford; the local Connecticut State Representatives; and SPARROW.8 The two ATSDR representatives also toured the Wallingford Municipal Waste Incinerator and held public meetings on September 5, 1990. Information gathered during those site visits is included in the appropriate sections of this public health assessment.
The population of Wallingford is 42,460.9 Based on 1980 census data, the Town is 98% white, 0.5% African-American, and 1.5% other. Twenty-five percent of the population is younger than 18; the median age is 32.4. An average 2.6 persons live in each household.
This town of mixed land use has residential, agricultural, industrial, commercial, and other facilities within its borders. Agriculture in the area includes dairy and dairy stock production and orchards. Industry includes chemical, primary and fabricated metals, plastics and rubber, printing and publishing, apparel and leather, and other manufacturing industries. Non-manufacturing industries include construction, transportation, utilities, services, and trade. See Figure 2 for an overview of Wallingford zoning.
Wallingford obtains its drinking water from multiple sources, including a surface water reservoir and three municipal wells. An estimated 600 private wells in the eastern part of the town are also used for drinking water. The municipal water is mixed from the various sources before being distributed to the town's residents. Approximately 75 percent of the water comes from surface waters in the reservoir; the remaining 25 percent comes from the three municipal wells.10 The reservoir collects surface water (e.g., streams and natural drainage) from the hills east of the town. The wells are in the low plain in the western part of the town, near the Quinnipiac River and north of the AC facility, the Municipal Solid Waste Resource Recovery Facility, the waste water treatment plant, and other industries. Town water is chlorinated and fluoridated.
The major surface water feature in Wallingford is the Quinnipiac River which runs generally north to south on the western edge of the town. This river receives both natural surface water runoff and various process waste water discharges. Those discharges are regulated through a CDEP administered discharge permit system.11 Major dischargers to the river include the municipal waste water treatment plant, AC, the Resource Recovery Plant, Connecticut Steel Corporation, Allegheny Ludlum Steel, and Bristol Myers. Discharge parameters regulated by the State include ultimate oxygen demand, biochemical oxygen demand, chemical oxygen demand (all measures of organic strength of waste water), total suspended solids, various metals, pH, residual chlorine, oil and grease, acute and chronic toxicity, ammonia, temperature, halogenated volatile organic compounds (VOCs), and individual organic species. Not all parameters apply to each discharger. The standards are based on the particular characteristics of the individual discharger's process waters.
Health outcome data available for Wallingford are of two types: health studies of the complaints made by Wallingford residents and existing health outcome databases. These two types of information are described in the following paragraphs.
Studies of Health Complaints from Wallingford Residents
CDHS has conducted three evaluations of data pertaining to the complaints from Wallingford. The Epidemiology Section of CDHS conducted the initial investigation of health complaints made by Wallingford residents in 1984.12 Also in 1984, the Toxic Hazards Section of CDHS evaluated the logs maintained by the residents and the information from the hotline.13,14 In addition, a contractor for EPA made a separate analysis of the health complaint logs in 1985,15 and ATSDR independently reviewed data from the hotline in 1990.16
Information from Existing Health Outcome Databases
Attempts were made to acquire a wide variety of health outcome data on Wallingford residents, because a wide variety of chemicals are being released into the air around Wallingford. The chemicals being released will be listed in the Environmental Contamination and Other Hazards section. Some of the chemicals are suspected to cause cancer, birth defects, and/or reproductive effects, depending on the extent and duration of exposure. In some studies, the mix of pollutants in urban air is linked to elevated rates of cancer. Little, if any data are available on the health effects that might result from exposures to the complex mixture of chemicals in the air in the Wallingford basin.
The types and availability of health outcome data were identified through discussions with CDHS. That agency maintains the following data sets: birth certificates, death certificates, fetal death reports, and cancer incidence. The first three data sets are available in computerized form for 1980-1988 down to the census tract for all standard variables, including cause of death, birth weight, birth defect, and demographic parameters. Information on cancer incidence is available down to the city/town level for 1935-1988 for the standard variables.
The Connecticut Department of Education, the Connecticut Hospital Association, and two hospitals in the Wallingford area also maintain relevant data sets. The Connecticut Department of Education maintains computerized information on attendance by school from 1984 to the present. Through an affiliate, (the Connecticut Hospital Research and Education Foundation, Inc.) the Connecticut Hospital Association has hospital discharge data for 1979-1990 down to the zip code level. Meriden-Wallingford (Meriden, CT) and Bradley Memorial (Southington, CT) Hospitals also have computerized information on hospital discharge. Those two hospitals were identified by CDHS as the facilities where most Wallingford residents are hospitalized.
Information from these data sets was obtained on cancer incidence, infant mortality, low birth weight, and hospital discharge. The hospital discharge data were not available for the daily or weekly intervals deemed useful for this public health assessment and thus will not be reported. Data on diseases possibly related to air pollution for the same periods might be useful in identifying clustering of pollution-related health effects. The study conducted by CDHS12 reports some relevant hospital discharge information which is discussed later in this assessment (see Health Outcome Data section). The CDHS study also describes a search of school attendance data; therefore, ATSDR deemed additional searches of the Connecticut Department of Education data bases to be unnecessary.
Community health concerns were identified through contact with SPARROW, Wallingford Town officials and residents, CDHS and CDEP staff, local media, and the State Representatives for the Wallingford area. ATSDR staff reviewed documents from CDHS and SPARROW, a videotape of a sick child, and an audio-tape of a 1985 radio talk show.
The symptoms reported by Wallingford residents as being linked to toxic substances in the air were listed in a 1984 letter to a CDHS staff member.17 This list is in Appendix Two along with the chemicals the residents suspected as possible causes of the symptoms. Suspected chemicals include toluene, ethyl benzene, butanol, xylene, methyl ethyl ketone, xylenes, acrylonitrile, and methyl methacrylate. The symptoms listed vary from headaches, numbness, and hyperactivity to nightmares, cramps, bladder infections, and miscarriages. Symptoms are grouped under specific organ systems such as the lungs, digestive tract, nervous system, etc. Residents reported that many of the individuals experiencing these symptoms did so at about the same time as the others reporting and on a periodic basis.17
Ten of the families reporting illnesses kept logs of their symptoms and when they occurred. The logs and similar data from a community hotline were evaluated by CDHS and are discussed in the Health Outcome Data Evaluation section.
In 1990, the chairperson of SPARROW provided to an ATSDR scientist an update on persons reporting symptoms in 1984.8 About 50% of SPARROW members reporting symptoms in 1984 had moved away from Wallingford. According to the SPARROW chairperson, those who moved reported that symptoms attributed to Wallingford have ceased. Similarly, it was noted that individuals on vacation usually stopped having symptoms. The SPARROW chairperson mentioned that, generally, members in the area reported fewer problems in 1990 than in 1984-85.
The chairperson of SPARROW also discussed with the ATSDR scientist her concerns about sewer gas as a possible cause of the reported symptoms. She has concluded that the homes of those reporting symptoms appear to be clustered near sewage pumping/holding stations and/or sewer lines. She proposed hydrogen sulfide (H2S) emanating from the sewer as a possible causative agent. Her concern about H2S began when low levels of H2S were detected near the town dump. Those results will be discussed in the Environmental Contamination and Other Hazards section. SPARROW members have observed that health problems lessened somewhat when a new sewage treatment facility was opened. The chairperson of SPARROW also expressed concern about the incineration of sewage waste at AC.
Community health concerns were also identified in public meetings held by ATSDR in 1989 and 1990.7,8 The 20 Wallingford residents attending the 1989 meeting reported experiencing symptoms, ranging from burning eyes to gastrointestinal upset, that they believed were related to the environment. Many of the attendees at this meeting reported odor problems in their neighborhoods. At the 1990 meetings four citizens reporting symptoms mentioned eye, sinus, and/or throat irritation, and headaches; one of the individuals also reported dizziness and shortness of breath. All four mentioned odor problems in their neighborhoods; both solvent and sewer smells were reported. The odors were reported to be worst in the summer.
The epidemiologic studies and databases selected for inclusion in this section are described in the State, Local, and Other Data portion of the Background section.
Studies of Health Complaints from Wallingford Residents
The epidemiologic study by CDHS in 1984 focused on the residents' reports as a cluster of gastrointestinal illnesses.12 A summary of investigative methods and their results is provided here:
- Interviewing individuals with complaints and their physicians to define the illness in time and place; information was obtained on 22 individuals from 10 families, including the group that first made complaints, plus individuals who voluntarily called CDHS in response to a letter to the editor of the local newspaper from the head of SPARROW. The 22 individuals reported the following specific complaints: upper respiratory infection (11), cramps/diarrhea (10), allergic phenomenon (10), earache (6), leg weakness/pain/cramps (5), and headache (1).
- reviewing school absenteeism records to determine whether school children were being affected at an unusual frequency during the first four months of 1984;
- reviewing emergency department records for 1983 and 1984 to determine whether there was an increase in visits for GI and respiratory illness:
Twenty of the 22 affected individuals had personal physicians; all were contacted. Of the 20 with physicians, 16 had been seen recently. The physicians cited the following causes for their patients' illnesses: upper respiratory infections - virus; abdominal cramps/diarrhea - virus, iatrogenic factors, IgA deficiency, or milk (lactose) intolerance; allergic phenomenon - contact dermatitis, allergic rhinitis, or multiple allergies; and earache - virus or bacteria. Only one of the five children with leg weakness/cramps was seen by a physician, and no diagnosis was made.
The rate of absenteeism for the first months of 1984 for all the primary and secondary schools in Wallingford was compared to that for the same period in 1983. There were no statistical differences between the two periods; and
The records for the World War II Veteran's Memorial Hospital revealed no difference between the emergency department visits for GI and respiratory illness during the first four months of 1983 and the same period in 1984. Specific numbers were not available for Meriden-Wallingford Hospital, the other hospital where many Wallingford residents are admitted. However, Meriden-Wallingford's infection control nurse conferred with the emergency department staff and reported no difference during the two time periods.
Based on its epidemiologic study, CDHS made the following conclusion: "Our evaluation suggests that the temporal and geographic clustering of symptoms among individuals in Wallingford is associated with common viral illnesses."12
Symptoms logs maintained by citizens from January through September 1984 were evaluated by CDHS in 1984.13 Information from six families encompassed 24 individuals who recorded dates, type of symptoms, and weather conditions. Some logs contained lengthy descriptions of symptoms and the specific time they were experienced; others had no specific time reference. Words used by individuals to describe their symptoms varied considerably; little standard medical terminology was used. CDHS grouped the symptoms into seven categories - gastrointestinal, musculoskeletal, central nervous system (CNS), skin, sensory, respiratory, and miscellaneous. The CNS classification included symptoms such as depression, irrationality, insomnia, and hyperactivity as well as dizziness, headaches, etc.
CDHS' analysis of the logs found that about half of the recorded symptoms fit the CNS category, followed by gastrointestinal, respiratory, musculoskeletal, skin, sensory, and miscellaneous. The nonquantitative nature of the data precluded any statistical analyses.
CDHS also evaluated information called into a "hotline" in November 1984.14 The hotline was established by the Town of Wallingford to allow citizens to document when symptoms were occurring. Callers were asked to give their name, address, time of day, and nature of complaint. Forty-seven of the 52 persons who called gave their address; they came from 13 different locations. Of the 47, 20 came from one location. Symptoms reported to the hotline included sleep disturbance, hyperactivity, muscle twitches, headaches, skin blotches, and menstrual irregularities. CDHS concluded that there was no clustering of any specific symptom by time of day.
EPA's contractor, ESA, evaluated data from the logs for the period January 18 to November 26, 1984, and from Wallingford's hotline for November 1984.15 Data were available from a total of 10 families. The data were organized into the following parameters: identity of family, address, date and time of complaint, and type and duration of symptom. ESA's evaluation found that most of the complaints occurred from 9:00 am to 9:00 pm peaking between noon and 6:00 pm. Two of the 10 families recorded 69% of the total complaints. One of the other eight families lived 7 1/2 miles south of Wallingford. The other nine families live in Wallingford and, in general, north of the pollution sources.
In 1990, an ATSDR physician reviewed data received on the hotline for the period November 7, 1984, to January 3, 1985.16 The 253 complaints were classified into the following categories: central nervous system (CNS) , respiratory , gastrointestinal , musculoskeletal , dermatologic , cardiovascular , and reproductive . The physician concluded that the symptoms listed in the CNS category were too diverse to represent a coherent toxic effect and that respiratory complaints should be considered the most prominent effect reported to the hotline.
Infant Mortality, Low Birth Weight, and Cancer Incidence Data
ATSDR used published data18 to determine the infant mortality rate and percentage of low birth weight births for Wallingford and Connecticut for the periods 1982-1984 and 1984-1987. The infant mortality rates per 1,000 births for Wallingford and Connecticut, respectively, were 5 and 10.4 for 1982-1984 and 8.1 and 9.2 for 1985-1987. The percentage of low birth weight births in Wallingford and Connecticut, respectively, were 4.5 and 6.6% for 1982-1984 and 5.2 and 6.6% for 1985-1987.
CDHS provided ATSDR with data on the number of cancer cases in Wallingford for a 25-year period (1964-1988). Those data were for 21 cancer sites and were divided into five-year intervals. The data were broken down by age and sex for each of the intervals. Data on the age groups 0-19, 20-29, 30-39, 40-49, 50-59, 60-69, and 70 or older were available for 1964-1968, 1969-1973, and 1974-1978. For the 1979-1983 and 1984-1988 intervals, the 70 or older group were divided into 70-79 and 80 or older.
ATSDR staff used the data to calculate the expected number of cases of cancer in Wallingford for each five-year period, age group and sex, based on the same variables for the State of Connecticut. The incidence rates for Wallingford, for the same variables, were also determined and compared to those of the State. In addition, ATSDR calculated standardized incidence ratios by dividing the age-adjusted incidence rate for Wallingford by the same rate for Connecticut. Age adjusting is a technique used to eliminate the effect of differences in the age breakdown of population groups. Table 1, which can be found in Appendix One, summarizes those data for each organ site for the 25-year period.
For each organ site, the number of cancer cases that occurred in Wallingford during 1964-1988 was not statistically greater than what was expected based on the incidence rates for Connecticut. The total numbers of cases (i.e., the total for both sexes and all age groups) of buccal cancer and multiple myeloma during 1964-1988 was statistically lower than expected. Statistically lower numbers of total cases occurred at the following organ sites during the specific periods: all organ sites during 1964-1968, buccal cancer during 1964-1968 and 1969-1973, and colon cancer during 1979-1973. Total numbers of cases of kidney cancer were statistically higher than expected during 1969-1973; the same was true of pancreatic cancer during 1969-1973.
Rates of cancer in women for the following sites and intervals were statistically lower: bladder (1974-1978), bone (1979-1983), buccal (1979-1983), buccal (1969-1973), leukemia (1979-1983), melanoma (1984-1988), multiple myeloma (1984-1988), multiple myeloma (1969-1973), thyroid (1979-1983), and uterine (1964-1968). For women, there were no organ sites for any five-year intervals that were statistically higher.
In men, rates of cancer were statistically lower than expected for the following organ sites and intervals: buccal (1964-1968 and 1969-1973), multiple myeloma (1974-1978), rectum (1979-1983), and all organ sites (1964-1968). Cancer rates were statistically higher than expected for men for the following sites and intervals; colon (1969-1973), kidney (1969-73), and pancreas (1969-1973).
In most ATSDR public health assessments, the Environmental Contamination section addresses "on- and off-site contamination" in separate sections. However, this public health assessment reviews contamination (pollution) data for the Wallingford area in a single section because no single source or site has been identified. The Town of Wallingford is treated as a "basin" with contamination (pollution) sources originating from both inside and outside the basin. All appropriate environmental data are reviewed in this section, but the emphasis will be on contaminants in the air.
Past efforts to evaluate air quality in Wallingford have focused largely on the AC facility and air studies associated with that facility. Consequently, the preponderance of air quality data available to ATSDR is related to that facility. To better understand the Wallingford air basin, a more thorough characterization is needed. Accordingly, other sources of air emissions are reviewed to put into better perspective their total impact on ambient air quality in Wallingford.
Air quality in Wallingford is impacted by a number of important sources, including numerous and varied industrial plant process and fugitive emissions, automobile and truck emissions, public utility emissions, residential heating and woodstove emissions, and similar emissions migrating into the Wallingford area from adjacent communities.
Two convenient sources of information regarding industrial-type emission sources are air pollution permit files and the recently initiated (since 1987) Toxic Chemical Release Inventory (TRI) database. Both sources of information were reviewed by ATSDR for this assessment and the findings are summarized in the following paragraphs.
Air Pollution Permits
The numbers and types of air permits issued for a particular area indicate the complexity and degree of processing activity taking place in that area. CDEP issued 69 air permits for point source air emissions for Wallingford.19 Unit operations or activities for which permits must be obtained include furnaces, boilers, incinerators, reactors, diesel generators, holding tanks, mixing tanks, and other processes which use exhaust stack or vent. A single permit can cover one or multiple units of a given type of process. In Wallingford, 31 permits are issued to AC; Bristol Myers holds seven permits, Byk Chemie six, and Wallingford Resource Recovery Facility and Wallace Silversmiths Inc. three each. Other facilities in the area with permits for point source air emissions include hospitals (for incinerators), steel companies (for process furnaces) and other miscellaneous companies (for boilers).
Toxic Chemical Release Inventory Data
The types and amounts of emissions must be understood to evaluate potential health implications. A source for data on the amount of industrial emissions is the TRI data base which is a record of major releases of potentially toxic chemicals to the air, water and land environment. The air portion of the database captures point source air emissions usually covered by air permits, and non-point air releases such as those that result from accidental releases or spills, or from fugitive process emissions. Fugitive process emissions include leaks from around pipes and valves, area emissions from materials handling, or storage or other releases not covered as point source emissions.
Several limitations of TRI data should be noted. The air release data in TRI may be estimates or actual measurements. Many of the reported data are estimates based on conservative (overestimated) scenarios. Consequently, the levels of emissions recorded in TRI are often biased on the high side.
Another limitation of the TRI database is that only certain industries employing more than a minimum number of workers are required to report releases. In addition, reporting is restricted to specific chemicals that are used or released above specified amounts.
Finally, it is believed that there have been and still are industries that do not report releases. Smaller industries may not be aware that report requirements exist or that they are responsible for such reports. It has been estimated that only about 60 percent of required reports are actually submitted.20 Because of the previously described and other uncertainties associated with the TRI database, numbers from TRI could be misleading when used to determine the public health implications associated with local air quality. Consequently, this assessment reviews the TRI database for general information regarding rough, order-of-magnitude estimates of industrial releases in the area and further to identify the more prevalent types of chemicals emitted to the air.
TRI data for 1987 and 1988 were reviewed.21,22 In 1988, over 1,750,000 pounds of chemicals were released to the air in Wallingford from the nine facilities reporting releases to TRI. AC was the largest with an estimated aggregate total release of one million pounds of chemical releases from the point and non-point sources at their facility. The second largest reported total emissions were about 250,000 to 300,000 pounds per year from Allegheny Ludlum. The third largest reported source of air emissions was Ulbrich (75,000 to 130,000 pounds per year). Several other industries in Wallingford reported emissions ranging from 1000 to about 65,000 pounds per year. The total amount of reported chemical releases into Wallingford's air decreased from 1987 to 1988. In the basin between New Haven (south of Wallingford) and Meriden (north of Wallingford), six additional industries reported air emissions of approximately 100,000 to 200,000 pounds per year.
In addition to identifying facilities that release chemicals into the air each year, the TRI database is useful for identifying actual chemicals released in an area, such as Wallingford. Table 2 (Tables 1 - 9 are in Appendix Two) lists the chemicals that were reported released in 1987 and 1988 in amounts greater than 1000 pounds per year. Because of the uncertainties in the database mentioned previously, range values, rather than precise numbers, are used in this table.
TRI data for 1989 were not available at the time of this review; however, AC furnished ATSDR with a copy of its 1989 TRI data. Review of these data shows a decrease in total emissions from AC over the previous two years. For the chemicals reported in Table 2, air releases from AC decreased for ethylene glycol, methanol, methyl acrylate, n-butyl alcohol, and 1,1,1 trichloroethane. Those decreases were by at least one of the three classification levels used in TRI to report releases. Emissions of 1,1,1 trichloroethane was reduced to zero in 1989. Only styrene increased, by one classification level. The decreases reported could have occurred as a result of process improvements or modifications, or because of refined estimating or monitoring techniques.
Review of the TRI database for the area from New Haven to Meriden shows large (>10,000 lbs./yr.), multiple-industry releases for 1,1,1 trichloroethane, methanol, toluene, and xylene. Those types of emissions, as well as others, could increase background levels of pollutants in Wallingford under certain meteorologic conditions.
Results of Ambient Air Studies
As mentioned previously, many of the source-specific data regarding air emissions were developed to characterize the potential impact of AC activities on surrounding areas. In 1984, a series of ambient air studies was undertaken by the U.S. EPA Region I Environmental Services Division and by TRC Environmental Consultants, Inc. under contract to AC.
The EPA studies conducted in 1984 evaluated ambient air quality in two ways. The first study, conducted in August of 1984, measured target species of organic compounds near the surface of an industrial waste landfill on AC property.23 Sample locations number one through three were on AC property; sample number four, which was considered to be background to the AC air samples, was located on industrial property across the street from the AC landfill. The highest values were found at sample location number one, which was sampled one foot above the soil surface. Samples two through four were taken four feet above the surface. Table 3 summarizes the results of the study.
The other EPA study, conducted in September 1984, took place during weather conditions (relatively high wind speeds) that were not conducive to detecting higher levels of organic pollutants that might exist.24 Findings were generally in the low parts per billion range. This study led to another EPA ambient air study in 1985 (reviewed in the following paragraphs).
In late June and early July, 1984, AC hired TRC Environmental Consultants, Inc., to do off-site ambient air monitoring in the vicinity of its facility.25 TRC conducted the monitoring using a mobile "tandem mass spectrometer" system known as "TAGAR". This rapid sampling and analytical method is van-mounted so that individuals who are sampling upwind and downwind conditions can quickly respond to changing wind conditions. Table 4 gives an overview of the ranges of values found for the parameters in this study.
In February 1985, the EPA returned to do additional ambient air sampling in the vicinity of the AC facility.26 Sampling was conducted during the day and at night under varying wind conditions. Upwind samples were taken 700-800 yards from the plant, and downwind samples were taken in varied locations, ranging from about 200 yards to 1.5 miles from the plant.
Five organic species (1,1,1 trichloroethane, benzene, toluene, methyl methacrylate and xylene) were found by EPA at levels of nearly 10 ppb or greater for an eight-hour average sample period both up- and downwind. The maximum eight-hour average downwind value for toluene was 76 ppb versus 40 ppb for an upwind maximum. The maximum eight-hour average downwind value for methyl methacrylate was 9.6 ppb versus 0.0 ppb upwind.
For instantaneous measurements, EPA found a maximum toluene value of 175 ppb at 200 to 300 yards downwind and a maximum value of 50 ppb at 1 to 1.5 miles downwind. EPA staff determined that those measurements were related to odors. When no odors were present, the measurements were between 2.5 and 13 ppb at both locations.
In summary, this study found periodic increased levels of toluene and methyl methacrylate downwind from the AC plant. The methyl methacrylate presence was sporadic in duration compared to toluene.
Indoor Air Studies
Several indoor air surveys have been conducted in response to citizen concerns about air quality in Wallingford. In March 1984, AC sponsored basement air sampling of two homes for acrylonitrile. No acrylonitrile was found in any of the six samples.27
In spring of 1985, an air inspector with the State Department of Environmental Protection (CDEP) sampled several residences in response to odor complaints (skunk, rotten egg) by Wallingford residents.28 The analytic results were not quantitative. The results ranged from no organic peaks found, to very low "petroleum type" peaks, to some benzene, decane, toluene, and other petroleum type peaks. It should be noted that some samples were not analyzed for one to two months after being taken.
In summer of 1985, CDEP studied the indoor air quality of four residences.29 Samples were analyzed for organic chemicals, dust, and metals. Table 5 gives summary results for the organic chemicals. Table 6 presents the metals findings.
Miscellaneous Air Studies
In addition to ambient air sampling in the vicinity of the AC facility, the sludge incinerator at the facility's waste water treatment plant was tested for point source emissions when originally permitted in 1974. Table 7 compares the measured emissions with the Connecticut Air Standards that applied to the facility at that time.
Also, in 1985, in conjunction with odor complaints, the CDEP analyzed for hydrogen sulfide (H2S) 1500 feet from the Wallingford dump.30 H2S was found at a maximum concentration of 9 ppb, which is greater than the detectable odor threshold of 0.47 ppb.
In 1988, in response to a concern about the health of Conrail employees in the vicinity of AC, air monitoring for process chemicals was undertaken. AC employed O.H. Materials Corp. to assist in the site sampling and analysis.31 AC also ran concurrent sampling.32 The CDEP conducted plant inspections during this period of both AC and the Wallingford waste water treatment plant.33 All results were low and suggested that, during routine operations, there was not a significant risk to health. The State findings were not conclusive regarding a possible previous exposure of a Conrail employee; however, the findings did indicate that the waste water treatment plant was the "more likely candidate" for intense odors at the time of the employee incident.
Also in 1988, as a result of community concerns about potential health effects from air exposure to industrial emissions on children playing baseball in a ballfield adjacent to AC, AC conducted fenceline, perimeter monitoring around its plant. The monitoring took place over a two-month period that fall.34 Table 8 summarizes the results of the survey.
Thus far, this discussion of air contaminants has focused on industrial types of emissions, largely because that is where community concerns are focused and, consequently, that is where the preponderance of data exists. As mentioned earlier in this section of this public health assessment, industrial air emissions are only a part of total air emissions in an area such as Wallingford. Other significant contributors of air emissions include area motor vehicle exhausts; commercial and residential fuel burning, including wood burning stoves; and emissions from businesses that are too small to be accounted for under industrial emissions sources.
In July 1989, the Air Compliance Unit of CDEP prepared a report for State Representative Mary Mushinsky that reviewed both AC air emissions data and other area emissions sources, such as those mentioned previously.35 Using local census and traffic data, coupled with representative emissions factors for fuel burning and motor vehicle exhausts, the State's calculations effectively showed that total volatile organic compounds (VOCs) emitted by the non-industrial sources were considerably greater than the emissions reported by AC. The State also noted that the non-industrial sources emitted a wide array of pollutants, many of which are considered more toxic than the emissions reported by AC.
The data on contaminants in the air reviewed here, are not adequate for making conclusions about whether exposure to contaminants in Wallingford's air has occurred or is occurring at levels of concern to public health. The evaluation of the air quality of an area as large as the Town of Wallingford must consider the effect of different meteorologic conditions and topographic features. Analysis of those factors requires that monitoring be done for at least one year and at several locations.
Information on Contaminants in Water
Even though contaminants in Wallingford's air have been identified by the citizens as the most likely cause of their complaints, water also needs to be considered as a possible pathway of human exposure. Some of the health complaints of the citizens are also consistent with waterborne contaminants. To explore this possibility, available information on surface and groundwater quality is reviewed. The Town of Wallingford's municipal water supply system and surface water are described in the Demographics, Land Use, and Natural Resource Use Section.
There is trichloroethylene (TCE) contamination in well number two of the municipal wells.10 The source of the contamination is believed to be the nearby Meriden landfill. Before this water is mixed with other municipal water, it is treated by air stripping to remove TCE. Water from Wallingford's municipal supply is checked as required by state and federal law and meets EPA's safe drinking water standards.
There are other known groundwater contamination sources in the city; including industrial landfills, junkyards, industrial pits or ponds, septage lagoons, and others. The CDEP maintains an inventory of such sources as a part of its water resources oversight functions.36-40 Wallingford routinely monitors its water quality, which should serve as a sentinel to detect any possible migration of contaminated water into its supplies.
As described in the Demographics, Land Use, and Natural Resource Use Section, the major surface water feature in Wallingford is the Quinnipiac River. Sampling data from this river for the contaminants described in the Information on Contaminants in Air portion of this section, were not available. However, CDEP discharge permits, as discussed earlier, were reviewed. No major long-term violations were identified.
Information on Contaminants in Soils, Sediments, and Food Chain
Sampling data for soils, sediments, and the food chain for the contaminants described in the Information on Contaminants in Air portion of this section, were not available. Based on available data and the nature of the health complaints, further investigation of those media was not indicated.
There may be individual areas with contaminated soils or sediments. The CDEP inventory of groundwater and surface water pollution sources, coupled with a long history of industrial activity suggests that it is likely that such contamination exists. Exposure to such contamination would be localized near the suspect sites.
Information about QA/QC was not available for many of the data reviewed for this public health assessment. It is assumed that adequate quality assurance and quality control measures were followed regarding chain of custody, laboratory procedures, and data reporting. The findings of this public health assessment are based upon the data as presented.
This section of the public health assessment is usually applied to a limited site of concern such as a Superfund site. Such hazards usually involve physical characteristics that could lead to bumps, falls, or trips at the site. It would not be feasible or relevant to the concerns raised in this petition to address physical hazards for the entire city of Wallingford.
The contaminant data reviewed previously identify the air pathway as the only completed exposure pathway. A pathway is considered complete when there is evidence that humans are being exposed to contaminants. The conclusion that there is a completed air pathway in Wallingford is based on the low levels of contaminants found in the community and the TRI data and thus is circumstantial. No direct evidence of human exposure was identified. There are also no data available to estimate exposure levels.
The other exposure pathways are considered to be potential exposure pathways, because data are lacking or are not adequate to conclude that human exposure has occurred or is occurring.
As mentioned previously, air is the only completed exposure pathway in Wallingford. The previous major section of this report discussed a number of industrial and non-industrial sources of air pollutants in the Town of Wallingford. Much of the source-specific industrial data focused on AC, primarily because it is a very large, highly visible industry in the area, and because it has been the center of considerable public concern. The chemical concentrations found in the studies associated with AC have on occasion identified downwind increases in some chemicals, such as formaldehyde, toluene, and methyl methacrylate; however, the measured values never exceeded the State's "hazard limiting values." Because of the focus on AC contaminants, air contaminants from other sources were not likely to be discovered.
Although some attempts have been made to do upwind and downwind monitoring, particularly around AC, ATSDR has not been able to find any broad-based sampling studies that try to characterize overall emissions in the city. For instance, other facilities in the industrial area around AC have been identified in odor complaints (sewer gas or "rotten egg" smell from municipal waste water treatment plant, and garbage odor from resource recovery plant, which opened after the health complaints in 1984); however, there are few or no data regarding the "non-odorous" compounds that could be emitted from other industrial sources.
Similarly, there are few or no data to characterize actual emissions from motor vehicle traffic or fuel burning for home heating purposes. The State's estimates of such emissions, based upon local population and traffic data and typical emission rates, indicate the non-industrial sources to be greater in amount than the known industrial source emissions.
Unfortunately, there are also no generally available meteorologic data for Wallingford. The lack of local meteorologic data confounds the assessment of pollutant dispersion patterns and the prevalence of pollutant build-up conditions, such as air stagnation or inversion episodes. Finally, lack of local meteorologic data precludes judging whether or not existing air monitoring studies have been done under typical, atypical, or worst case conditions.
The ultimate measure of the effect of air pollutant exposures to the residents of a community is the measurement of actual pollutants where people live, work, or play. For public health assessments, this is the human "receptor" that completes the environmental human exposure pathway. In Wallingford, only a few such studies have been conducted (see previous section of report). Those studies were done in homes and at a ball field after health concerns were expressed by the community. Again, there is no way of knowing whether those studies were worst case situations with respect to location, meteorology, or total city emissions. It should be noted that all studies measured combined air pollutants in the study area; in the homes, the studies may have also measured air contaminants generated inside the dwelling. It is generally recognized by environmental health professionals that materials in the home such as stored cleaners, pesticides, carpeting, and some insulations can contribute significantly to air contamination levels found in the home.41
In summary, it can be seen that the air exposure pathway is extraordinarily complex for a town such as Wallingford. Some elevated levels of benzene, toluene, and formaldehyde have been found downwind of AC; however, those compounds also arise from other non-industrial combustion sources in significant amounts. Of the measured compounds, only ethyl acrylate and methyl methacrylate would appear to be solely related to industrial sources.
As discussed in the introduction to this section, the rest of the exposure pathways are potential sources of human exposure to contaminants.
Potential Water Pathway
There is demonstrated TCE contamination of one well in Wallingford's municipal water supply system. Through treatment of the well water and quality checks, the community's water supply is kept within Safe Drinking Water Standards. In the context of this public health assessment, that potential exposure pathway does not appear to be significant. In addition, the wide geographic distribution of a small number of cases and highly varied nature of the symptoms reported by the residents do not appear to be consistent with water contamination. Some of the symptoms such as nausea and diarrhea are consistent with some water-borne bacteria or virus. However, a larger percentage of the population would be reporting illness if these agents were the cause.
Likewise, the surface water pathway does not appear to be a significant potential source of human exposure. It is recognized that discharges to the Quinnipiac River produce some degradation of the quality of water in the river; however, it is not likely to be degraded to an extent that endangers human health (assuming there is no catastrophic release of toxic materials directly to the river). The river water is not used by the citizens of Wallingford as a potable water source or for extensive swimming. The incidental ingestion of river water by individuals recreating on or in the water is likely to be so limited as to be inconsequential, particularly in light of the limits placed on the contaminating sources discharged to the river. It should also be noted that polluted groundwater, such as might be associated with old land disposal operations, could migrate, in some instances, to the Quinnipiac River.42 The CDEP has considered this possible pathway and believes that it does not present a significant human health hazard.43
Other Potential Exposure Pathways
As described in the Environmental Contamination and Other Hazards Section, data are not available to evaluate these pathways.
As discussed in the preceding section, exposure of humans to contaminants in Wallingford (i.e., completed pathways) has been demonstrated only for the air pathway and only on a circumstantial basis. No valid estimates of exposure levels to airborne contaminants could be made. However, it is not possible to exclude the potential for harmful exposure to airborne contaminants. That inability is due to the lack of long-term monitoring data on air pollution in the Wallingford area and to the lack of information on specific meteorologic parameters for the Wallingford air basin.
The descriptive data available to ATSDR indicate that the ground- and surface-water pathways do not represent plausible routes for human exposure. Few individuals have or are being exposed to any sort of contaminants in drinking water. In addition, there appears to be little or no interaction between the surface water pathway and the residents of Wallingford. There are inadequate data to make any conclusions about the soil, sediment, or food chain pathways.
One of the usual objectives of the Public Health Implications Section is to evaluate whether the exposure levels identified for a specific exposure pathway is causing or may result in health effects in humans. That evaluation is not possible in this document because of the data gaps identified in the Environmental Contamination and Other Hazards Section.
The Toxicological Evaluation portion of this section will identify possible health effects from exposure both to the chemicals listed in Tables 2 - 5 and to the complex mix of air pollutants known to be present in the Wallingford area. In addition, the available health outcome data will be evaluated and the community concerns addressed.
This section will identify possible health effects from exposure to the chemicals listed in Tables 2 - 5, and to the complex mix of air pollutants known to be present in the Wallingford area. There is no indication from the limited monitoring done that there are any exposures high enough to cause the effects listed for the specific chemicals, with the possible exception of eye irritation due to exposure to formaldehyde. Data are lacking on the levels of air contaminants from automotive emissions, industry, and other sources cited in CDEP's 1989 letter.35
High levels of a complex mix of airborne contaminants have been linked to elevated rates of allergic disorders, acute upper respiratory infections, influenza, bronchitis, cardiovascular disease, lung cancer, asthma, and emphysema.44 Increases in levels of airborne contaminants have been linked with increases in school absences,45 emergency department visits,46 and mortality rates;47 and decreases in lung function.48 The health effects cited here were observed in urban areas where there was a mix of automotive and industrial pollution. Airborne contaminants can both cause illness directly and influence the rate of diseases which result from other causes, as can be observed from the previously described list of health effects. An example is the relationship between air pollution and upper respiratory infections. Airborne contaminants can affect the young, elderly, and those with chronic health problems at lower doses and more severely than the average population.47
Two indirect measures of the effect of airborne contaminants were not elevated in a limited evaluation of those parameters. CDHS checked school attendance and emergency department visits for respiratory illnesses for the first four months of 1983 and 1984.12 No elevations were identified. This CDHS study is described in the Health Outcome Data Section and is discussed in the Health Outcome Data Evaluation subsection of this section.
Table 9 indicates which organ systems could be affected by the chemicals identified in the TRI database (Table 2), the ambient air studies (Tables 3 and 4), and the indoor air study (Table 5). The headings are similar to those used in CDHS's evaluation of the complaint logs.13 A major difference is that behavioral/psychological effects are presented as a separate heading rather than being included in central nervous system (CNS).
The information in Table 9 is provided to indicate that the chemicals that either are or could be in Wallingford's air, can cause many of the symptoms listed in the complaint logs. However, nearly all of those symptoms would occur only after high levels of exposure. The exception is formaldehyde; very low levels of that chemical can cause eye, nose, and throat irritation in some individuals. There is no indication from the limited air monitoring studies conducted that high levels of exposure to chemicals are occurring. Comprehensive long-term monitoring of the air in Wallingford could determine whether the levels of exposure necessary to cause adverse effects are possible.
Evaluation of Health Complaints
Investigating environmentally related health complaints involves answering three basic questions: 1) can an average or typical set of symptoms be identified from the complaints being received; 2) are the number of symptoms or health effects being reported clustered by time, place, and/or person; and 3) can exposures to toxic agents be identified which could be causing the symptoms or health effects? This section will use those three questions to evaluate the data presented in the Studies of Health Complaints from Wallingford Residents portion of the Health Outcome Data section and in the Environmental Contamination and Other Hazards section.
Reviewers of the complaint logs or hotline data were unable to answer the first question by identifying an average or typical set of symptoms.12-16 Exposure to a specific chemical agent or agents usually results in a distinct set of symptoms or health effects. Identification of that set of typical symptoms or effects is an important step in determining how many people are being affected. That set of typical symptoms is also vital for eliminating from a study those individuals who are sick due to other causes. The wide range and diverse nature of the health complaints made, especially those deemed CNS-related, makes meaningful analysis of this situation very difficult. Another problem in identifying a typical set of symptoms is the possible impact of the complex mix of contaminants apparently present in Wallingford's air. That mix could cause a far wider range of symptoms than is observed for a single agent. The problem might be resolved by undertaking a more complete characterization of the air contaminants in Wallingford. Those data could be used to determine whether symptoms or health effects are associated with the contaminant mix.
Another problem with trying to identify symptoms typical of a mix of contaminants is that the mix may cause a few relatively mild symptoms in most individuals and a broader set in a sensitive few. Public meetings held in 1989 and 1990 identified several individuals who reported symptoms (burning eyes, headaches, etc.) and exposure circumstances typical of air pollution.7,8 No attempt was made to quantify other symptoms, possibly related to contaminants in Wallingford's air, that might have been occurring at the time of the initial complaints in 1984. The relatively small number of individuals reporting health problems could have been only a small portion of those experiencing health effects from airborne contaminants.
Regarding the second question, on clustering, the available data indicate that the health complaints from Wallingford are sharply clustered by person, somewhat clustered by time, and not at all by place. The complaints appear to be confined to about 10 families and no more than 30 individuals as indicated in the initial evaluation of the situation by CDHS in April 1984.12 The majority of the complaints came from two families.
Through various means, SPARROW and CDHS attempted to identify additional individuals who thought they were experiencing symptoms related to contaminants in the air or to other environmental sources. Those means included evaluating school attendance, emergency room visits, and calls to Wallingford's hotline; writing letters to area physicians requesting identification of possible cases; and soliciting experiences via a radio talk show and numerous articles in area newspapers. However, the data review in March 198517 and site visits by ATSDR in 1989 and 19907,8 did not reveal significantly different numbers of individuals with the wide range of symptoms identified in the complaint logs.
It should be noted that the ability to identify more individuals with complaints would partly depend upon identifying a specific set of symptoms that are typical for the situation. The difficulty in determining those typical symptoms was discussed previously.
As mentioned previously, there is some evidence that complaints were clustered by time of day and perhaps by meteorologic conditions. EPA's evaluation of the complaint logs revealed a clustering of complaints between noon and 6 pm.17 The EPA report also identified 34 days when three or more families experienced symptoms. A meteorologist consulted by CDHS concluded that conditions that would maximize exposure to air pollutants (i.e., thermal inversions) occurred on 19 of those days.49 However, the evaluation did not provide the total number of inversions occurring in 1984, so it is not possible to determine if inversions occurring on 19 of any 34 days is abnormal.
The lack of clustering by location is indicated by Figure 1, in which the residences of those making complaints are plotted. Most of the locations are widely separated.
The last of the three questions posed at the beginning of this section was whether exposures to toxic agents could be identified which might cause the symptoms or health effects of concern. As discussed in the Environmental Contamination and Pathways Analyses sections, the answer is no. However, more extensive sampling over a longer period would be necessary before the possibility of exposures hazardous to health occurring could be eliminated.
Evaluation of Cancer Incidence Data
The number of cases of cancer in Wallingford from 1964-1988 is what would be expected based on the rate for Connecticut, except for buccal cancer and multiple myeloma. Numbers of cases for those types of cancer were statistically lower than expected. There was no more than one period when the case numbers were statistically higher or lower for any of the 21 organ sites evaluated, except for buccal cancer and multiple myeloma. For those two, there were two five-year intervals with lower than expected cases.
The failure to identify any excess cancer cases may be an indirect reflection of air quality. As discussed in the Toxicological Evaluation section, there is good evidence linking air pollution in several urban areas to elevated rates of lung cancer. In addition, several of the individual contaminants released into Wallingford's air are suspected to cause cancer. AC, the single largest point source of air contaminants, has been in operation since 1940, and Wallingford was industrialized before then. There would appear to be sufficient time between the opening of AC and other facilities and the period for which cancer data were evaluated, 1964-1988, to account for the long lag-time between exposure and induction of disease commonly observed with cancer. The lack of elevated rates of lung and other types of cancer may indicate that air quality in Wallingford is better than urban areas where excess rates have been identified.
Evaluations of cancer incidence data have limitations. The cancer incidence data used do not include information on personal risk factors (smoking, diet, alcohol, etc.) or on occupational and environmental exposures to chemicals. Analyses of those data can only be descriptive and cannot be used to determine associations with possible agents. There is an inherent five percent chance that any excess in observed cancer cases is due to random variation alone.
However, the availability of data for the 25-year period evaluated here overcomes a common limitation with analyses of this type, which is statistical power. The ability to detect small effects (i.e., statistical power) increases as the total number of cases evaluated increases.
Another limitation of this evaluation is the choice of the state of Connecticut as the comparison population. Differences in the racial make-up, and socioeconomic status of Wallingford and the state as a whole could result in variance in incidence rates. The comparison of Wallingford to a community or communities in Connecticut of similar racial make-up and socioeconomic status could eliminate this problem. However, use of a smaller population would reduce statistical power.
The 1980 census indicates that the socioeconomic status of Wallingford is similar to Connecticut. However, Wallingford is 98% White, 0.5% African-American, and 1.5% other, while Connecticut is 92% White, 7% African-American, and 1% other. In conducting this evaluation of cancer incidence, it was decided the statistical power gained by using the whole state overweighed the influence of the small racial differences.
This section addresses the community health concerns expressed by SPARROW and brought up at the public meetings in 1989 and 1990. The health concerns of SPARROW include a wide range of symptoms and are listed in Appendix 2. The group has associated the symptoms with airborne contaminants and, as an alternative, sewer gas and/or living near sewer lines. The complaints listed in 1989 and 1990 focused on eye, nose, and throat irritation; headaches; and dizziness.
The Original Health Complaints
The data available to ATSDR suggest that the complaints expressed by SPARROW and other Wallingford citizens are limited to a small portion of the 40,000 or more residents of Wallingford. The complaints came from about 30 individuals, whose residences are, mostly, widely separated. The complaints, at least in some people, have developed into treatable health problems.8 One report suggests that the complaints might be associated with air inversions.49 The limited air monitoring done in Wallingford did not identify exposures to chemicals that could cause the symptoms listed in the symptom logs kept by the residents. The anecdotal information that symptoms lessened or ceased when an individual left the area suggests that the symptoms may be partly related to either airborne contaminants or concern about exposure to toxic substances.
There are at least two possible explanations for the cause of the health complaints from this relatively small group of individuals. The first possibility is that airborne contaminants caused most of the symptoms experienced. The number of people reporting symptoms might be small because only the most sensitive individuals were sick enough to complain. A much larger group of citizens could have experienced symptoms such as mild eye irritation without connecting them to airborne contaminants.
The second possible explanation is concern about possible exposure to contaminants. It has been fairly well documented that concern about exposure to contaminants in the environment can lead to or compound illness.50 Reaction to concern about the well-publicized environmental violations of American Cyanamid could at least partially explain some of the health problems experienced by SPARROW members.
There appears to be no way to determine which of the two possible causes of these health complaints (or any other explanation) is correct. Making a determination might have been possible if a study had been done in 1984 of the occurrence of symptoms possibly related to airborne contaminants, and if adequate air monitoring data had been available. The extensive publicity about the health complaints and the time lapse since then, however, render invalid any future study of the situation in 1984.
Concern about Sewer Gas
The suggestion by SPARROW that sewer gas and/or living near sewer lines is a possible cause of the health complaints does not appear to be plausible, based on a review of toxicologic data on hydrogen sulfide (H2S). SPARROW suggested H2S as the chemical of concern in the sewer gas. It can be produced when sewage is improperly treated or as organic material decays.
Review of the literature on H2S indicates that this chemical does not have the ability to cause most of the symptoms mentioned by SPARROW in Appendix Two. Inhalation of about 20 parts per million of H2S can cause dizziness, nausea, and irritation of the eyes, nose, and throat.51,52 At levels greater than 150 ppm, the sense of smell is deadened and above 350 ppm, the respiratory system becomes paralyzed in less than a hour. Loss of consciousness and death can quickly follow. People are able to detect the characteristic "rotten egg" smell of H2S at about 0.00047 ppm, which is more than 40,000 times lower than the level at which health effects begin to occur.
More Recent Health Complaints
The health complaints registered in the 1989 and 1990 public meetings may be consistent with health effects resulting from air pollution and thus may indicate that a health problem is occurring. It should also be noted that the reported symptoms could also be due to infectious agents, workplace chemicals, or toxic substances in the home.
This potential for health problems related to airborne contaminants could be evaluated by long-term monitoring of Wallingford's air. Any exposures of possible health significance could then be remediated and/or investigated for health consequences.