PUBLIC HEALTH ASSESSMENT
NEW BEDFORD SITE
NEW BEDFORD, BRISTOL COUNTY, MASSACHUSETTS
New Bedford Harbor drains the Acushnet River into Buzzards Bay in southeastern Massachusetts. Extensive polychlorinated biphenyl (PCB) and heavy metal contamination have been detected in the estuary that drains the river, a portion of which is exposed as a mudflat at low tide. This contamination has also been detected in sediment sampled from the remainder of the harbor. As a result, the Massachusetts Department of Public Health (MDPH) has restricted fishing in the area since 1979.
This ban has largely been effective in reducing exposure to PCBs via ingestion of contaminated seafood as evidenced by the Greater New Bedford PCB Health Effects Study (GNBHES). PCB serum monitoring conducted during this study demonstrated a low prevalence of environmental PCB exposure and the majority of the participants reported consuming no seafood harvested from harbor waters known to be contaminated. This study, however, did identify some individuals who consumed locally caught contaminated seafood and a trend toward elevated serum PCB levels in these individuals was observed.
A remote potential exists for hazardous lead and cadmium exposure in children consuming seafood harvested outside of restricted waters. Such risk assumes scenarios such as ingestion of high levels on a daily basis for extended periods of time. Although metal levels are elevated in regional seafood, it is unlikely that unsafe metal exposure via ingestion of these organisms is occurring to any significant extent.
Currently, PCBs are volatilizing from areas in the estuary and PCB levels in ambient air monitored from these areas are elevated nearly five hundredfold above the Massachusetts air standards. Based on animal studies, chronic exposure to PCB levels detected in these areas may be associated with increased risk of cancer development. Removal of these sediments is necessary to remove the health risks associated with exposure to them. The scheduled dredging of PCB contaminated sediment will result in a temporary elevation of PCB levels in ambient air at the areas being dredged. Individuals near the area during the dredging period will not incur an increased cancer risk since chronic exposure to elevated PCB levels will not occur.
Dredging of sediments containing the maximum levels of PCB contamination may result in the reduction of contamination levels in seafood. The extent of this attenuation and the depuration time necessary to achieve safe levels are, however, uncertain. Continued monitoring of contamination levels in edible aquatic wildlife is therefore essential to determine that time when restrictions on seafood harvested from waters in the area can be either eased or lifted.
Animal studies have demonstrated adverse health effects resulting from exposure to PCB levels such as those that would be expected following dermal contact with shoreline sediments in the area with maximum contamination. Such adverse health effects include immune system suppression, gastrointestinal cysts, decreased thyroid hormone secretion, fat accumulation in the liver and increased cancer risk.
Incineration of sediments containing greater than 4,000 parts per million of PCBs has been selected as part of the remedial plan in order to destroy these contaminants and reduce the associated health risk. These sediments, however, contain high levels of lead and it is possible that significant lead levels could be emitted during the incineration process. Numerous safeguards are planned to be implemented to ensure that elevated human exposure to lead does not occur as a result of incineration. Such measures include monitoring lead levels emitting from the incinerator exhaust stack during two series of emissions testing. Air dispersion models will then be developed so that lead levels at the most likely points of exposure can be estimated. The rate at which sediments are burned will then be regulated so that the estimated lead exposure does not reach levels of concern. Uncertainties do, however, exist that render lead exposure estimates inaccurate. Ambient air monitoring, especially for lead, will provide an indication of the extent to which the population is exposed to airborne contaminants that may or may not be associated with incinerator emissions. Such monitoring will enable environmental officials to consider possible sources of contamination in air and possibly take corrective actions.
Based on the information reviewed, ATSDR has concluded that this site is of public health hazard because of the risk to human health resulting from ongoing exposure to PCBs via ingestion of contaminated fish within harbor waters and dermal contact with PCB-contaminated sediments. The New Bedford Harbor Site has been evaluated by ATSDR's Health Activities Recommendation Panel (HARP) for appropriate follow-up with respect to health activities. Since PCB registry and serum lead monitoring programs are currently operating within the MDPH, the Panel determined that additional follow-up health activities are not indicated at this time.
The New Bedford Harbor site is situated in southeastern Massachusetts and drains the Acushnet River into Buzzard's Bay. The Acushnet River borders the city of New Bedford to the east and the towns of Acushnet and Fairhaven to the west. The site is divided into numerous regions based on geographic landmarks and PCB contamination levels. Four areas containing elevated sediment PCB concentrations in the Acushnet River estuary (greater than 4,000 parts per million [ppm]) have been identified. These "hot-spots" totaling five acres are proximal to the New Bedford shore, where the Aerovox Corporation, a manufacturer of electrical components, is located.
The Wood Street Bridge connects the city of New Bedford with the town of Acushnet. Hot Spot "A", which is contiguous with the shoreline at the Aerovox plant, covers 1.72 acres and is 1,202 feet south of this bridge. Area "B" encompasses 2.6 acres of sediment off the New Bedford shoreline and is situated 2,090 feet south of the Wood Street Bridge. Areas "C" and "D" are located 2,300 feet south of the Wood Street Bridge and encompass 0.2 and 0.4 acres respectively. During the design of the remediation for the "hot-spot" area further sampling was conducted to more accurately define those areas with sediment PCB levels greater than 4,000 ppm. Six Hot-Spot areas were delineated. Hot Spots "A" and "B" were essentially divided generating two additional "hot-spot" areas. Wetlands are located in the region encompassing the "hot-spots" (Area I in Table 2) on the Acushnet shoreline, immediately east of the Aerovox plant (See Figure 1).
The Acushnet River estuary which contains the "hot-spot" areas is a 230 acre region that extends from the Wood Street Bridge to the Coggeshall Street Bridge, 1.6 miles south. A wetland area (Area II in Table 2) is situated in the estuary on the Acushnet shoreline approximately 2,500 feet south of wetlands area I. The 750 acre lower harbor is bounded to the north by the Coggeshall Street Bridge and to the south by two sea walls. One sea wall extends from the New Bedford shore on the west and one from the Fairhaven shore on the east. Fairhaven is the town immediately south of Acushnet. The harbor drains into Buzzard's Bay through an opening between the two walls. Pope and Fish Islands lie in the lower harbor approximately one mile south of the Coggeshall Street Bridge and are traversed by route 6, which runs through New Bedford and Fairhaven. (See Figure 2.)
Water flow in the estuary is influenced by the tidal movement of Buzzards Bay. The sediments in the estuary near the "hot-spot" areas show a gradual decline from both shores towards the center of the river channel, and are exposed as mudflats at low tide. Low tide water elevations near the "hot-spot" areas at this time range from 1.6 to 2.2 feet below mean sea level (MSL) (NUS, 1984).
Factories are predominant in the area along the New Bedford immediately south of the Aerovox Plant and are situated primarily along the shore of the estuary. A playground is, however, located in a cove on the New Bedford shoreline, one mile south of the "hot-spot" region. Wharves and piers align the New Bedford shore of the lower harbor. Residential areas are located along the Fairhaven shoreline of New Bedford Harbor. A plant operated by Cornell-Dubilier Electronics (CDE) is situated on the New Bedford shoreline approximately 2,500 feet south of the seawall. Fort Rodman State Park is also situated on the New Bedford shoreline approximately one mile south of the harbor sea walls. Fort Phoenix lies along the Fairhaven shore immediately outside of the harbor confines.
Both the Aerovox Corporation and CDE manufactured electrical components and used PCBs in the production of capacitors. More specifically, Aroclor 1242 was predominantly used from 1947 to 1971 after which both companies used Aroclor 1016 until 1977 when usage of PCBs in the manufacturing process ceased entirely. Both companies also used Aroclors 1252 and 1254 in smaller quantities. Reports by the United States Environmental Protection Agency (USEPA) indicate that the Aerovox company discharged PCB contaminated waste water directly into harbor sediment and that defective capacitors were also deposited in the estuary. The New Bedford municipal waste water treatment system also received contaminated waste waters from these industries (EBASCO, 1989).
PCBs pertain to compounds containing two six-carbon rings with two to ten chlorine atoms attached. Mixtures of these different compounds are called Aroclors and were widely used in the electronics industry for the manufacture of capacitors and transformers. The insulating properties of these mixtures as well as their chemical stability even under high temperatures made them suitable for this use. These compounds are also readily soluble in organic (carbon-containing) solvents and tend to accumulate in plants and animals exposed to PCB contaminated media.
In 1979, fishing restrictions were imposed due to elevated levels of PCB contamination detected in New Bedford Harbor waters and sediment as well as in living organisms (biota) that inhabited the area. Harvesting of any aquatic wildlife is prohibited within the harbor waters enclosed by the sea walls to the south and the Acushnet River at the Wood Street Bridge to the north (Area I). The Buzzard Bay waters immediately south of the harbor (Area II) were closed to lobster harvesting and the taking of bottom feeding fish (eg. eels, flounder, etc.). Lobster harvesting was prohibited in the remainder of the landlocked Buzzard Bay waters south of the harbor (Area III). See Figure 3. Warnings in Portuguese and English against fishing in estuary and harbor waters were posted when the ban went into effect. By 1990, these signs had weathered and the lettering had become faded. In 1992, USEPA and the United States Army Corps of Engineers (USACE) placed new warning signs in the harbor area. These signs are written in English, Spanish, and Portuguese.
As a result of the elevated levels of contamination detected in the estuary, New Bedford Harbor was placed on the USEPAs National Priorities List (NPL) in 1982. Environmental data characterizing sediment, biota, soil, and surface waters in and around the harbor were collected during the previous ten years, compiled and released in 1983 (Metcalf & Eddy, 1983). These data were used in the development of a feasibility study which was completed in 1984 and presented numerous remediation strategies. This feasibility study drew extensive commentary and it was determined that additional studies were necessary before a remediation alternative could be selected. In 1988, the Engineering Feasibility Study (EFS) was completed by the USACE which included additional environmental monitoring, modeling of sediment dispersion and a pilot dredging and disposal study.
Sediments moderately contaminated with PCBs were dredged from Sawyer's Cove, approximately one mile south of the "hot-spot" area. The dredgings were disposed in an on-shore landfill immediately south of the cove. Extensive monitoring was conducted at this time in order to determine the impact of these activities on contaminant migration. As a result of the EFS, the "hot-spot" area was delineated and determined to be one operable unit of the site. A remedial plan to dredge the "hot-spot" area was accepted and a record of decision (ROD) was signed in April of 1990.
In September of 1990 a feasibility study for remediation of the remainder of the harbor sediments was completed. One month later, a model estimating food chain PCB contamination based on various sediment exposure scenarios was released. In January of 1992, a plan to remediate the remainder of the estuary, lower harbor and upper Buzzard's Bay was proposed by USEPA. In May of 1992, a supplemental plan to further remediate PCB-contaminated sediment detected in Buzzard's Bay was proposed by USEPA. This public health assessment will address the health impact of exposure to contaminants disseminating from the entire harbor and is being conducted in conjunction with a forthcoming ROD for the remainder of the site.
The Director of the New Bedford Board of Health, Suzanne Condon, Director of the Bureau of Environmental Health Assessment (BEHA) and ATSDR Project Officer at MDPH, and William Strohsnitter, Environmental Analyst at MDPH conducted a site visit on April 25, 1990. The harbor shellfish warden, provided a tour of the site by boat. At the time of the tour, the tide was receding, however, and the mudflats were not yet exposed. Considering the mudflats at the Aerovox Plant were not exposed, the depth of the waters was such that the passage by boat was possible to a point approximately 800 feet south of the Wood Street Bridge. The mudflats did not appear to be accessible from the shoreline at the Aerovox Plant since a steep embankment led from the plant to the estuary waters. While no persons were seen in the harbor during the site visit, local harbor and health officials have observed children playing in the area. Swimming has also been observed at other times in the cove, near the playground one mile south of the Aerovox Plant. This fenced playground was visible from the estuary.
The eastern shoreline appeared to be predominated by wetlands immediately east of the Aerovox Plant and residential areas further south. A quarry operation and scrap yard containing derelict automobiles and tires were also observed on the eastern shore from the estuary waters. The tour was conducted on an overcast weekday in the late morning and little human activity within the harbor waters was observed. Although the land surface leading to the eastern shoreline was not steep, encroachment of the "hot-spot" areas from this shore line was observed to be difficult since it would involve wading or swimming a distance of 500 feet.
Signs printed in both English and Portuguese prohibiting any type of fishing activity within the harbor waters were posted on both the eastern and western shorelines as well as at the Wood Street Bridge. Although there was no evidence of vandalism to these signs, they did appear to have faded over the years as a result of ambient exposure. No fishing activities were observed in the harbor waters during the visit. Three buoys were sighted in bay waters immediately outside of the harbor sea walls, however it could not be determined if they marked lobster traps.
The land surface along the western shoreline at the "hot-spot" areas was not visited since the private property on which it is located is closed to visitors. Entrance to the Aerovox Plant is accessible only through a guarded gate. Permission to visit the factory grounds was not granted at the time the visit to the area was made.
On October 1, 1993, William Strohsnitter, Environmental Analyst for the Community Assessment Unit and Jeffrey Purvis, Chief of the Community Assessment Unit within BEHA at the MDPH toured accessible land areas adjacent to the estuary with the Director of Public Health for the City of New Bedford. The playground at Sawyer's Cove, which is across the cove from where dredged sediments are to be deposited, was visited. The playground was vacant on this sunny weekday morning. The fence between the playground and the shoreline was in disrepair and the shoreline was readily accessible from the playground. Evidence of trespassing in this area by older individuals was observed at this time.
The area surrounding the estuary where the "hot-spots" are situated is zoned for industrial, commercial and residential use. According to the 1980 federal census, the population within a three mile radius of the site is approximately 90,000 and constitutes over 70 percent of the total population for Acushnet, Fairhaven and New Bedford. In 1990 the federal census counts for these municipalities were 99,922 for New Bedford, 9,554 for Acushnet and 16,132 for Fairhaven. The population for the town of Dartmouth was 27,244. This town is also part of the Greater New Bedford area but does not lie within a three mile radius of the "hot-spot" area. According to the census conducted by each of these municipalities, the population numbers were 106,237 for New Bedford whose population count is most recently available from the census conducted in 1991 and 15,608, 8,985, and 27,269 for Fairhaven, Acushnet, and Dartmouth respectively whose local census counts were conducted in 1992.
The Aerovox Plant, situated at Belleville Avenue and Howard Street, is located in an area that contains nine other industrial plants. These factories, starting at a point 900 feet south of the Wood Street Bridge, occupy 5,000 feet of the New Bedford shoreline along the Acushnet River Estuary. The plant is adjacent to a factory owned by the Acushnet Company, a major manufacturer of golf equipment and is also in immediate proximity to a factory owned by the Cliftex Corporation, where men's clothing is manufactured (G. Hall, 1984). These three companies are among the leading employers in the New Bedford Area. Textile and metal product manufacturing as well as paper processing constitute other operating industries situated in the immediate area.
The area along the Acushnet shoreline across the estuary from the site is undeveloped. A sewage treatment substation is located 1,500 feet southeast of the site and a residential area is situated 1,500 feet northeast of the "hot-spot" area. Residential areas also are predominant in the region immediately west of the industrial area. The Saint Joseph Elementary School, a public library, the Brooklawn Park and a 10-bed nursing facility are located in New Bedford within a half mile radius of the Aerovox Plant.
The New Bedford shoreline south of the Coggeshall Street Bridge contains fish processing plants and numerous wharves. In 1989, 316 fishing vessels were moored in New Bedford Harbor and accounted for an annual catch of 90.4 million pounds outside of contaminated waters. In addition, 180 motorboats and yachts were docked in New Bedford Harbor during 1983. A public boat launch and the Union Wharf as well as numerous boat and fishing equipment repair businesses are located along the Fairhaven shoreline. In 1983, it was estimated that 2,700 people in the Greater New Bedford area were either directly or indirectly employed by the fishing industry (NUS, 1984).
The catching of finfish, shellfish and lobster is prohibited in New Bedford Harbor as a result of the ban promulgated by the MDPH in 1979. Recreational fishing activities along the shorelines of New Bedford Harbor is, however, still observed by local officials. Recreational as well as commercial boating activities are ongoing in the harbor area. In addition, there are at least two public swimming areas proximal to New Bedford Harbor. The Fort Phoenix State Preservation, located on the Fairhaven shoreline immediately exterior to the harbor sea wall and the Fort Rodman Beach area, situated on the New Bedford shoreline 1.6 miles south of the harbor sea wall both contain designated swimming areas. The Fort Rodman beach area is also approximately one half mile south of the CDE plant on Buzzard's Bay. Another municipal swimming area is situated on the New Bedford shoreline of Clark's Cove (figure 2). The municipal swimming areas in New Bedford were closed in 1989 due to sewage contamination of bay waters resulting from municipal sewerage system overflows. Repair was done on the city sewer lines in 1990 and as a result coliform counts subsided significantly. Swimming activities consequently resumed in bay waters in the summer of 1990.
There are two recreational areas situated along New Bedford shoreline of the estuary. One playground, previously mentioned, is located within the group of factories which contains the Aerovox Plant and lies approximately one mile south of the "hot-spot" area. An athletic field is situated immediately interior to the harbor at the sea wall extending from the New Bedford Harbor shoreline. Two parks are also situated in Fairhaven, inland from estuary waters. Livesy Park is situated 1,400 feet inland immediately north of Coggeshall Street and Cushman Park is located in Fairhaven, 800 feet inland immediately south of Route 6.
As previously mentioned, the fishing industry is a substantial component of the economy in the Greater New Bedford area. In the 1830s the whaling industry in the area prospered and New Bedford experienced an influx of Portuguese seamen. Approximately 50% of the population of New Bedford is of Portuguese ancestry and 35% of the total population in New Bedford speak only Portuguese. Results of the fish consumption survey issued to participants of the Greater New Bedford PCB Health Effects Study (n=840) indicated that 15.4% of those surveyed reported that they were currently eating seafood that was locally caught (and presumably PCB-contaminated) by themselves, friends or relatives. Most of the participants (61.5%) however, reported that, at the time of the survey (1984-87), they were not consuming locally caught contaminated seafood (MDPH, 1987).
The residents of New Bedford and Acushnet receive their drinking water from Great Quitticus Pond in the town of Lakeville approximately 10 miles north of the site. Currently, there is no known groundwater usage in New Bedford for drinking or irrigation purposes. Two of the three drinking water wells that supply the majority of the population of Fairhaven are located in Mattapoisett, the town immediately east of Fairhaven. These wells are four and five miles from the "hot-spot" area. The Dartmouth municipal well fields are also distant to the harbor waters, located approximately four miles inland to the west of the harbor. One well field, situated in East Fairhaven, is also greater than three miles from the "hot-spot" area. Private groundwater wells are reported to be drilled in Fairhaven with the closest being one mile south of the "hot-spot" area, 1,800 feet inland of estuary waters.
Concurrent with the completion of the EFS, the MDPH in conjunction with the U.S. Centers for Disease Control (USCDC) and the Massachusetts Health Research Institute (MHRI) conducted the Greater New Bedford PCB Health Effects Study (GNBHES). The study was designed to assess the extent of exposure to PCB contamination by measuring PCB concentrations in the serum of randomly selected residents from the Greater New Bedford area. Fish consumption and occupational histories were also obtained in order to elucidate plausible routes of exposure to PCB contamination. Finally, blood pressure measurements were taken to test the hypothesis of an association between elevated serum PCB levels and hypertension (MDPH, 1987).
The Childhood Lead Poisoning Prevention Program (CLPPP) is also housed within the MDPH. Data from this program should be considered for Heath Assessment purposes due to the possible exposure to lead via ingestion of contaminated seafood. This ongoing program is mandated with the surveillance of serum lead levels which are determined in conjunction with a child's routinely scheduled physician's visit. The program also conducts extensive childhood serum lead screening in those regions where access to health care is known to be low. Evidence of blood lead level determination is required of children residing in the state prior to their entry into day care or elementary school programs.
The results of the CLPPP surveillance are published annually in a report which assesses the need for lead poisoning prevention services in municipalities throughout the Commonwealth. Included in this report are data pertaining to the number of children aged six months to six years residing in each city and town, the percentage of total housing units in each of these municipalities constructed prior to 1950 and the prevalence rate of lead poisoning (serum lead levels greater than 25 micrograms per deciliter) observed in each city and town throughout the state. The data presented in this public health assessment are from those reported in the needs assessment for the periods between October of 1988 and September of 1989 as well as for July of 1990 through June of 1991.
In 1979, the citizens of the greater New Bedford area expressed concern over the possible contamination of edible aquatic organisms with PCBs and the resultant exposure via ingestion. As a result of this concern, two pilot PCB exposure studies were conducted in 1981. The scope of serum PCB monitoring was expanded in the GNBHES conducted between 1984-1987. This prevalence study demonstrated the extent of human exposure to PCBs among the general population in greater New Bedford. The MDPH anticipated further concern over possible PCB exposure and as a public service, provided serum PCB monitoring for concerned citizens not selected for participation in the GNBHES.
The concern over elevated cancer rates in New Bedford were addressed by the Community Assessment Unit (CAU) within MDPH. A report detailing the cancer experience in the City of New Bedford was released by the CAU in October of 1990.
Currently, some citizen concerns regarding the site are focused on when safe consumption of seafood harvested from harbor waters can resume. PCB and metal contamination of the harbor waters and associated sediments has resulted in the loss of an expansive commercial and recreational fishing resource to the greater New Bedford community.
In anticipation of the scheduled incineration of contaminated harbor sediments, local citizen groups have raised concerns over possible exposure to incinerator emissions. Representatives from the MDPH attended a public meeting convened by USEPA in 1991 to hear these concerns.
As part of the ATSDR Environmental Health Education Program for Physicians and Health Professionals, an overview of the public health assessment process was presented at Grand Rounds conducted at St. Luke's Hospital on November 14, 1991. A local physician at these rounds raised the concern over the safety of consuming fish served in local restaurants.