PUBLIC HEALTH ASSESSMENT
McCORMICK & BAXTER CREOSOTING COMPANY (PORTLAND)
PORTLAND, MULTNOMAH COUNTY, OREGON
ENVIRONMENTAL CONTAMINATION AND OTHER HAZARDS
Sampling has been conducted on site for surface soils; subsurface soils; groundwater; NAPLs (nonaqueous-phase liquids [e.g. nonsoluble liquids]); and storm water. Off site sampling was conducted for surface soils, sediment, crayfish, and fish (Large Scale Sucker).
Those sampling data and supporting site-related information suggest that contaminants associated with wood treatment have been released to on-site soils, groundwater, and storm water runoff. Data also suggest that contaminants have migrated off site to sediments and river biota. River water quality also is likely to have been affected to some extent by site releases, but sampling information is not available for confirmation. Citizens' concerns about odor also suggest releases, but sampling information is not available for confirmation. This section identifies contaminants ATSDR representatives have selected for evaluation in later sections of this public health assessment to determine whether exposure to them has public health significance. However, ATSDR's identification of contaminants here does not imply that human exposure has occurred or that exposure would actually result in adverse health effects.
Contaminant selection considered the following factors:
ATSDR's (EPA's) 1991 Toxic Chemical Release Inventory (TRI) (7), a database that contains information about annual releases of toxic chemicals to the environment, shows (1) approximately 80,000 pounds (total) of airborne releases of volatile organic compounds and gases were reported by three industrial facilities located between one-fourth of a mile and 1 mile from the site and (2) another 113,000 pounds (total) reported by two facilities located between 1 and 1½ miles from the property. All the facilities are on the west side of the river. Concentration information is not available for TRI data; hence, those airborne contaminants are not addressed further in this section of the assessment.
The specific contaminants selected to be addressed further in the public health assessment are listed in data tables organized according to the media in which they were found (Tables 1 through 8 in Appendix B). Those tables include, where available, the public health assessment comparison values ATSDR used for selection. Environmental Media Evaluation Guides (EMEGs) are estimated comparison concentrations that are based on health effects information determined by ATSDR for its Toxicological Profiles for specific chemicals. Cancer Risk Evaluation Guides (CREGs) are estimated comparison concentrations for specific chemicals based on an excess cancer rate of one in a million persons and are calculated using EPA's cancer slope factors. Reference Dose Media Evaluation Guide (RMEG) comparison concentrations are based on EPA's estimate of the daily dose below which exposure to a contaminant is unlikely to cause adverse non-cancer health effects. Proposed Maximum Contaminant Levels (PMCLs) represent EPA's proposed drinking water contaminant concentrations considered protective of public health. Action Levels (ALs) are concentrations in drinking water, which, when exceeded, require implementation of a regulatory-based response protocol.
NOTE: Some of the sample data tables include information for polychlorinated dibenzodioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). PCDDs and PCDFs constitute a family of 210 structurally related chemical compounds. The PCDDs and PCDFs reported for samples taken for this site are predominantly low-potency compounds (e.g., the octa and hepta compounds); 2,3,7,8 tetrachlorodibenzo-p-dioxin, the most potent of the compounds, occurs at a much lower concentration than the rest. The EPA has developed a tentative methodology--the Toxicity Equivalency Factor (TEF)--for reporting the cumulative concentrations of all PCDDs and PCDFs in terms of their relative potency compared to 2,3,7,8-tetrachlorodibenzo-p-dioxin. ATSDR provides PCDD/PCDF TEF values in the data tables.
A. On-Site Contamination
Tables 1 through 5 (Appendix B) present the maximum documented values of the on-site contaminants; these are considered in developing the Public Health Implications section of this assessment. This section summarizes from those tables the specific organic compound and metal found at the highest concentrations. Identification of contaminants here and in the tables does not imply that human exposure has occurred or that exposure would actually result in adverse health effects.
Surface Soils (Table 1)
arsenic |
5,100 ppm |
Subsurface Soils (Table 2)
arsenic |
61,000 ppm |
Groundwater (Table 3)
zinc |
260,000 ppb |
NAPL*; below ground (Table 4)
metals |
not reported |
copper |
15,000 ppb (mean value) |
B. Off-Site Contamination
Tables 6 through 8 (Appendix B) present the maximum documented values of the off-site contaminants; these are considered in developing the Public Health Implications section of this assessment. This section summarizes from those tables the specific organic compound and metal found at the highest concentrations. Identification of contaminants here and in the tables does not imply that human exposure has occurred or that exposure would actually result in adverse health effects.
arsenic |
11 ppm (mean value) |
River Sediment (Table 7)
manganese |
690 ppm |
Crayfish (Table 8)
zinc |
15 ppm (mean value) |
Large Scale Sucker (Table 8)
zinc |
7.4 ppm |
C. Quality Assurance
and Quality ControlReference documents indicate that quality control protocols were followed for sampling and
laboratory analyses.
D. Physical and Other Hazards
ATSDR did not observe any substantive physical or other hazards associated with the site.
PATHWAYS ANALYSES
Discussion of specific human exposure pathways in this section does not imply that adverse
health effects are associated with them; health issues are discussed in the Public Health
Implications section. ATSDR identifies human exposure pathways by examining environmental
and human components that might lead to contact with contaminants. A pathway analysis
considers five elements: a source of contamination, transport through an environmental medium,
a point of exposure, a route of human exposure, and an exposed population. Completed exposure
pathways are those for which the five elements are evident, indicating that exposure to a
contaminant has occurred in the past, is currently occurring, or will occur in the future. ATSDR
regards people who come in contact with contamination as exposed; for example, people who
drink water known to be contaminated, or who reside in an area with contaminated air, or who
work or play in contaminted soil are considered exposed. Potential exposure pathways are those
for which one or more of the elements is not clearly defined but through which exposure is
plausible. Potential pathways indicate that exposure to a contaminant could have occurred in the
past, could be occurring now, or could occur in the future. Elements of completed and potential
exposure pathways are summarized in Tables 9 and 10 (Appendix B). Although the information
available is ample for identifying several specific completed and potential human exposure
pathways, data for confirming the degree and duration of exposure are not available.
A. Completed Exposure Pathways
Principal Completed Exposure Pathways
Air: On Site (During Operation)
Although sampling data are not available to identify the specific airborne contaminants or concentrations on site (or off site) while MB operated, ATSDR's observations of active wood treatment plants and awareness of treatment chemical potency lead the agency to conclude that MB's workers were substantively exposed to volatilized chemicals and contaminated dust through inhalation. Visitors and trespassers were not exposed to as great a degree.
Process Chemicals, Wastes, Soils: On Site (During Operation)
ATSDR's observations at active wood treatment plants and awareness of associated chemical potency lead the agency to conclude that MB's workers, during operations, were substantively exposed to contaminants associated with process chemicals and wastes and contaminants in surface soils (Table 1), principally through skin contact and incidental ingestion. Some of the contaminants in process chemicals and wastes also are represented by sampling data obtained for nonaqueous-phase liquids (NAPLs) (Table 4) encountered below ground.
Air: Off Site (During Operation)
Nearby residents (some of whom reported plant-related odors) and nearby workers were exposed to volatilized organic chemicals and probably some contaminated dust through inhalation while the plant operated. Sampling data are not available to identify the specific airborne contaminants or their concentrations.
Other Completed Exposure Pathways
Because of the long-term potency of many of the contaminants, most of the exposures described here will continue until remediation is effected.
Soils: On Site
Evidence exists that trespassers occasionally breach the perimeter security fence intentionally and enter the site. Trespass is believed to result in exposure to contaminants in surface soils now and in the future (until remediation is effected), principally through skin contact and incidental ingestion. Table 1 identifies some of the on-site surface soil contaminants and their respective concentrations.
Soils: Off Site
ATSDR believes residents and workers on nearby properties have been exposed, are now being exposed, and will be exposed in the future to low levels of contaminants deposited on the ground by wind in off-site areas while the facility was in operation. Other urban sources are likely to have contributed to the soil contamination. Exposures to contaminated surface soils occur off site principally through skin contact and incidental ingestion. Table 6 identifies some of the off-site surface soil contaminants and their respective concentrations.
River Sediment: On Site and Off Site
Children have been observed walking and playing along the shoreline on site in the past, and ODEQ representatives learned that two boys received skin burns on their legs while playing on the adjacent downstream shoreline when the river level was low. Although the site security fence extends into the river to prevent entry along the shoreline, ODEQ representatives note that the fence is breached periodically and does not fully prevent access to the on-site shoreline area. Therefore, ATSDR believes trespassers have been exposed, are now being exposed, and will be exposed in the future (until remediation is effected) to contaminants in surface sediments on site, principally through skin contact. Some former workers probably were also exposed through skin contact. Similar exposures can occur on the immediate downstream shoreline off site. Table 7 identifies some river sediments contaminants and their respective concentrations. Contaminants include those released from the site and possibly some released from additional sources upstream.
Crayfish and Fish: Off Site
The Oregon Health Division and Department of Fish and Wildlife have issued an advisory cautioning the public about commercial crayfish harvesting, and the shoreline area and paths to the shore are posted. ODEQ is not aware of any recreational crayfishing activity. ODEQ believes that the advisory has deterred commercial crayfishing in the immediate area, but commercial crayfishing continues in downstream areas. This information indicates that people who fish and crayfish in the area adjacent to the site have been exposed, are now being exposed, and will be exposed in the future (for a period after remediation is effected) through ingestion to chemicals taken up by crayfish and fish. Table 8 identifies some of the contaminants and respective concentrations present in tissue samples taken from crayfish and the large scale sucker. Contaminants include types released from the site and possibly from additional sources along the river.
Surface Water: Off Site
ATSDR believes that shoreline users, recreational and commercial fishermen, water skiers, and swimmers in the immediate area have been exposed, are being exposed now, and will be exposed to contaminants released from the site in the future (until remediation is effected), principally through skin contact and incidental ingestion. Investigations conducted to date have not included river water quality data for the site vicinity. Table 1 (on-site surface soil), Table 3 (on-site groundwater), Table 4 (on-site below-ground NAPLs), and Table 5 (on-site storm water) identify some of the contaminants released to the river; however, site-related concentrations in the river are expected to be much lower than represented in the tables, which represent contaminants in on-site media, because of dilution and chemical degradation processes.
Air: On Site and Off Site (After Operations)
A nearby resident reports continuing periodic chemical odors both winter and summer. ATSDR
notes there are considerable chemical processing and petroleum storage activities on the west
bank of the river and elsewhere in the area; the EPA's Toxic Chemical Release Inventory shows
that some of those activities release volatile chemicals to the air. ATSDR's review of current site
conditions and periodic remedial activities suggests that chemicals on site continue to volatilize
at least to some limited extent, especially during warm weather, and some contaminated particles
are likely to be transported by wind. Although wood treatment operations have ceased, the
reports of continuing odors indicate that people in the immediate area (including workers on site
and at nearby off-site businesses and also residents) are being exposed to airborne contaminants
through inhalation. The specific source or sources of periodic chemical odor exposure might
never be clearly defined, and air-related exposure might not terminate after site cleanup is
effected.
B. Additional Exposure Pathway Issues
Potential Exposure Pathways
Soils: On Site
Remedial workers have the potential to be exposed to contaminants in soils (Tables 1 and 2) through incidental ingestion, inhalation, and skin contact as cleanup progresses if precautionary measures are unexpectedly inadequate for the conditions encountered. Future users of the site after remediation is complete also have the potential to be exposed to subsurface contaminants through incidental ingestion, inhalation, and skin contact if the protective soil cover is breached.
Air: On Site
If, after remediation, chemicals in the subsurface (Tables 2, 3, and 4) volatilize and migrate upward through the protective soil cover, or if cracks develop in the soil cover, future site users could be exposed to contaminants periodically through inhalation. Exposure, should it occur through these mechanisms, might not be substantive because the chemicals reported through sampling are of low volatility.
Sediment: On Site and Off Site
Full remediation of site-related contaminated sediments along the shoreline and in the river might be difficult to achieve, and river currents conceivably could expose subsurface contaminants in the future. Therefore, ATSDR believes that persons using the shoreline after remediation might be exposed to contaminants, principally through skin contact.
Other Pathway Considerations
Groundwater: On Site and Off Site
ATSDR representatives toured the site vicinity with city water department personnel, who
confirmed that all residences and businesses in the area are connected to the public water system.
ATSDR representatives also reviewed water well data on file with the U.S. Geological Survey
and the Oregon Water Resources and found no wells recorded at locations that would likely be
affected by the site. No apparent past or present users of groundwater contaminated by site
releases (Table 3) were disclosed, and future users of that resource are unlikely.
PUBLIC HEALTH IMPLICATIONS
In this section, ATSDR discusses health effects of chemicals that people were exposed to on the site, evaluates available health outcome data, and addresses specific community health concerns.
To determine whether people can get sick from exposure, ATSDR begins by estimating daily exposure doses for each contaminant of concern by each route of exposure. We use information about levels of contaminants and about people's activities to estimate the exposure dose. The estimated exposure dose is then compared to a Minimal Risk Level (MRL), which is an estimate of daily exposure to a contaminant below which noncancer disease is unlikely to occur. To develop the MRL, ATSDR relies on information from scientific studies of the effects of exposure to contaminants on people and animals. If an exposure dose exceeds an MRL, or if no MRL has been developed, the estimated exposure dose is then compared to other health-based guidelines, such as the Environmental Protection Agency (EPA) reference dose, or to doses that resulted in adverse health effects in people or experimental animals as described in the scientific literature. These comparisons take into account the uncertainties inherent in relying on harmful effects produced in animals to predict the possibility of effects in people, as well as differences among people.
In the United States population as a whole, cancer occurs in the lifetime of one in three people (8). It is very difficult for scientists to determine who will get cancer, but we do know that exposure to some contaminants can increase the chances (or risk) of getting cancer. Even if a person gets cancer, scientists and physicians typically cannot know the cause of the person's cancer. To determine whether exposure at this site might cause cancer, a numerical increase in the risk of cancer is estimated using the estimated exposure dose and a cancer slope factor developed by the EPA specifically for each cancer-causing chemical.
Although potential and completed exposure pathways are described in detail in the Pathways Anaylses section, pathways and the people involved with the pathways are reiterated in this section to provide context for the reader. Adverse health effects of exposure to contaminants of concern are discussed. Health effects of exposure to some of the contaminants found at this site are not known.
ATSDR concludes that plant workers were exposed to the wood treating chemicals arsenic, pentachlorophenol, and creosote as well as to dioxins/furans (predominantly the low-potency compounds) during the plant's operation. These exposures are believed to have been through incidental ingestion (i.e., swallowing by accident during other swallowing activities) of soils on site. These exposures were at levels of public health concern. Additional exposures which may have occurred through direct skin contact with the chemicals or inhalation of the vapors and dust in the air could increase the health risk. Workers could have inhaled additional chemicals that originated off the site; several other industrial facilities in the site's vicinity have reported (in the EPA Toxic Release Chemical Inventory [TRI]) releasing unknown concentrations of chemicals into the air. A discussion of potential health effects associated with worker exposure to each chemical or chemical class is presented later in this section.
Trespassers and visitors to the plant during its operation would have been exposed to the same chemicals to which the workers were exposed. Because of the short exposure time, it is highly unlikely that they would become ill from being exposed to most areas of the site.
Two boys playing in shallow water along the shoreline on or adjacent to the site reportedly received skin burns, apparently from contact with hazardous chemicals. The site is believed to be the source of the contamination. Other people might encounter chemicals along the shoreline at levels capable of burning the skin. Site-related chemicals that can burn the skin are discussed later in this section.
People who eat contaminated fish and shellfish can be exposed to contaminants. Evaluation of contaminant levels in fish and shellfish indicate that, for people who subsist on crayfish or suckers over a long time, health effects from exposure to polychlorinated dibenzodioxins and dibenzofurans might be expected. It is not known whether anyone ingests contaminated fish to that extent. Those potential health effects are discussed later in this section.
Nearby residents and workers were exposed when they breathed contaminated air during the plant's operation. The site might not have been the only source of air contaminants. Other nearby facilities have reported releases. Because there is no available air data, those inhalation exposures cannot be evaluated. Residents have reported health effects that are known to be experienced by individuals with no known exposure to hazardous waste, but are also consistent with inhalation exposure to site-related contaminants. Site-related chemicals that can cause those health effects are discussed later in this section.
Residents might also be exposed to airborne contaminants during remediation. Real-time air monitoring would show whether airborne contaminants released by remedial activities would be at a level of health concern.
People who use the Willamette River near the site for recreation might be exposed by skin contact and incidental ingestion to any contamination that migrated into the river water. Studies conducted to date have not included river water sampling. It is likely that site-related contaminants are diluted enough in the water that there is no health threat to recreational water users.
Although the facility has been closed and fenced, remedial workers and people who trespass onto the site or wander near the site at the river's edge can be exposed to contaminants by incidentally ingesting on-site soil and sediments in the river and at the river's edge. Because remedial workers wear protective gear and because intruders are not likely to stay on the site for long, remedial workers and others are not likely to swallow contaminants often; it is unlikely that they will get sick this way. However, people who wander near the site at the river's edge might expose their skin to contaminated sediments. Contaminants in the sediment do not appear to be at levels that would cause any effects; however, in one case, two children who waded near the site reportedly received skin injuries consistent with the type of damage exposure to site-related contaminants can cause.
People who live or work nearby can incidentally ingest contaminants in soils on properties where they live or work. Results from several residential soil samples show that contaminant levels are so low that it is unlikely that anyone will get sick from incidentally ingesting soil. Limited soil data from adjacent industrial property also show that contaminant levels are so low that workers are unlikely to get sick from incidental soil ingestion; however, we do not have enough soil sample information to be reasonably sure that the contaminant concentrations found represent the true concentrations in that area.
Potential Health Effects of Chemicals
Sickness related to occupational exposures to the wood treating chemicals arsenic, pentachlorophenol, and creosote is discussed below. Dioxins and furans are contaminants commonly found with pentachlorophenol at wood-treating facilities and have been found at this site. Therefore, those chemical groups are included in this discussion. Health effects of eating dioxin-contaminated fish are included in this discussion as well.
Coal-tar creosote is a complex mixture of more than 300 compounds, including polycyclic aromatic hydrocarbons (PAHs), phenol and cresols. PAHs have been found at this site. There are no sampling data confirming phenol and cresols on site, and compounds related to phenols (substituted phenols) were found only at very low levels in on-site soil. However, because workers worked with creosote, we assume that they were exposed to phenol and cresols. Therefore, health effects of exposure to phenol, cresols, and PAHs are discussed. Because these chemicals can injure the skin upon contact and the respiratory system upon inhalation, potential health effects for people who wander along the shoreline and for people who live around the site and breathe contaminated air are included in this discussion as well. There are no environmental data confirming that the latter two groups of people are exposed at levels of health concern. However, health effects consistent with exposure to creosote have been reported.
Arsenic
Arsenic is a naturally occurring element. Pure arsenic is a gray metal-like material; arsenic is usually found combined with such other elements as oxygen, chlorine, and sulfur. Arsenic combined with these elements is called inorganic arsenic. Inorganic arsenic is used as a preservative for wood to make it resist rot and decay; it is predominantly inorganic arsenic which has been found as a contaminant at this site.
Plant workers
Plant workers were exposed to arsenic through incidental ingestion, inhalation and skin contact. The maximum arsenic concentration found on site was 5,100 parts per million (ppm) in soil.
Inorganic arsenic has been recognized as a human poison since ancient times. There are numerous studies conducted on people who swallowed inorganic arsenic at doses similar to those ATSDR estimates workers received. The results of those studies are discussed below (9).
Perhaps the single most characteristic effect of long-term oral exposure to inorganic arsenic is a pattern of skin changes. This pattern includes a darkening of the skin and the appearance of small warts or corns on the palms, soles, and torso. While these skin changes are not considered to be a health concern in their own right, a small number of the corns might ultimately develop into skin cancer. Swallowing arsenic has also been reported to increase the risk of cancer in the liver, bladder, kidney, and lung. The Department of Health and Human Services (DHHS) and the EPA have determined that arsenic causes cancer in humans. Arsenic in the soil at the site is at levels which can lead to a low increased risk of cancer in workers.
Other effects of exposure to arsenic at levels workers may have sustained included irritation of the stomach and intestines, with symptoms such as pain, nausea, vomiting and diarrhea; impaired nerve function causing "pins and needles" in the hands and feet; blood vessel damage; anemia; and liver damage. Off-site arsenic exposures of this magnitude are probably not possible.
Pentachlorophenol (PCP) and dioxins/furans
PCP is a substance made from other chemicals. It does not occur naturally. PCP is used as a wood preservative and is released to the air by evaporation from treated wood surfaces. It enters the soils as a result of spills. Polychlorinated dibenzo-p-dioxins and dibenzofurans, also called dioxins and furans, are classes of compounds that do not occur naturally and are not intentionally manufactured (except as reference standards for analytic laboratories). However, they can be inadvertently produced as impurities. Technical grade PCP usually contains dioxins and furans as impurities.
Plant workers
Plant workers were exposed to PCP and dioxins/furans through incidental ingestion, inhalation and skin contact. The maximum PCP concentration found on the MB site was 4,800 ppm in soil. Dioxins and furans concentrations are given as a single 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalent concentration; the maximum dioxin/furan concentration was 0.38 ppm. Although there are no data from which to estimate actual inhalation or skin exposure doses, workers at wood treatment facilities are known to inhale and take in through the skin significant levels of PCP and dioxins/furans.
Because of PCP's frequent contamination with dioxins/furans, wood-treatment plant workers who work with PCP are generally exposed to dioxins/furans as well. Studies conducted on wood-treatment workers exposed to PCP actually investigate health effects of exposure to PCP contaminated with dioxins/furans (10).
Various studies of wood treatment workers exposed to PCP show that the blood, kidneys, and skin can be affected (10). Exposure was associated with aplastic anemia (defective functioning of the blood-forming cells), reduced kidney function, and skin and eye irritation. The lengths and levels of exposure that cause harmful effects in people are not well defined. Studies in rats and cows also show an association between PCP exposure and blood, kidney, and skin disorders. Exposure to PCP, dioxins and furans is known to cause chloracne in people. Chloracne is a skin problem characterized by cysts and abscesses on the face, chest, and abdomen.
The EPA has classified PCP and dioxins/furans as probable human carcinogens (10,11). PCP is classified as a probable human carcinogen because studies have shown an association between ingesting pure PCP and cancer in mice; dioxins and furans are classified as probable human carcinogens because studies have shown an association between dioxin ingestion and cancer in rats. The levels of PCP and dioxins/furan in the site's soil correspond to a low increased risk of cancer for workers.
Crayfish and sucker eaters
ATSDR staff members estimated dioxin/furan exposure doses for people who eat contaminated crayfish and suckers on a regular basis. We assumed that people rely solely on crayfish and suckers as their sole source of fish and shellfish (we assumed they ate between one and four six ounce meals of crayfish and/or suckers a month). The levels of dioxin/furans in crayfish and suckers correspond to levels associated with a low increased risk of cancer for people who subsist on crayfish and/or suckers for many years. In addition, although there have been no well-substantiated reports of reproductive toxicity in people who ate dioxins/furans, studies in rats indicate that eating dioxin might cause spontaneous abortions (11). It is not known whether anyone relies on crayfish and/or suckers harvested near the site as their sole source of fish and shellfish. For people who occasionally eat contaminated crayfish, no adverse health effects are expected.
Creosote, phenol, cresol,
and polycyclic aromatic hydrocarbons (PAHs)
Coal-tar creosote is a widely used wood preservative. It contains phenol, cresol, and PAHs. PAHs make up a class of chemicals. There are more than one hundred PAHs.
Plant workers
Plant workers were exposed to creosote through incidental ingestion, inhalation and skin contact. Because creosote is a mixture, its concentration cannot be measured. PAHs, however, were measured in soil. Maximum concentrations of carcinogenic PAHs found on site were 420 ppm benzo(a)anthracene; 210 ppm benzo(a)pyrene; 1,000 ppm benzofluoranthenes; 1,900 ppm chrysene; 22 ppm dibenz(a,h)anthracene; and 56 ppm indeno(1,2,3-cd)pyrene.
There is little information on the health effects of creosote exposure in workers. Brief worker exposure to large amounts of creosote can harm the skin, eyes, nervous system, and kidneys. Studies of workers exposed for a longer time to lower levels of creosote through the skin describe burns and irritation of the skin and eyes as the most frequent symptoms.
In addition, animal studies of phenol exposure and human studies of cresol exposure indicate that inhalation of those compounds can irritate the respiratory tract (13,14). Creosote inhalation effects are further discussed below in the Community Health Concerns Evaluation section.
Based on animal studies, the DHHS and the EPA have decided that the PAHs benzo(a)anthracene, benzo(a)pyrene, benzofluoranthenes, chrysene, dibenz(a,h)anthracene and indeno(1,2,3-cd)pyrene probably cause cancer in people (15). Those PAHs have been found on site. In laboratory experiments, they have caused tumors in animals when the animals breathed them, ate them, or had long periods of skin contact with them. Studies of humans show that individuals exposed by breathing or skin contact for long periods to mixtures that contain PAHs and other compounds can also develop cancer. PAHs in the soil at the site are at levels which can lead to a low increased risk of cancer for workers.
Nearby residents
Little is known about the health effects of coal-tar creosote inhalation; however, mouse studies show inhalation of beechwood creosote, which has some of the same components as coal-tar creosote, can cause irritation to the respiratory tract (12).
Phenol and cresols are constituents of coal-tar creosote. Animal studies of phenol exposure and human studies of cresols exposure indicate that those compounds can irritate the respiratory tract when inhaled (13,14). Although the results do not give a time frame, irritation probably begins within minutes. Guinea pigs exposed to phenol at higher concentrations for a longer time period (more than a month) developed pneumonia, bronchitis and other serious lung problems (13). Pulmonary edema and hemorrhage and perivascular sclerosis (hardening of the tissue) in the lungs was seen in animals exposed to cresols for one month (14).
Pentachlorophenol is another chemical commonly used at the site. There is very little information on inhalation effects of pentachlorophenol; however, it appears to cause inflammation of the upper respiratory tract and bronchitis in people upon chronic, high-dose occupational exposure in the presence of other chemicals (10).
Since we do not know what chemicals people were smelling or their concentrations, we cannot determine whether the health effects mentioned above could be related to the site.
Historical wading exposure
Boys were playing in the river at the edge of the site when they reportedly received burns.
Sampling of river sediment found chemicals that are also found in creosote. Several reports in
the literature describe skin irritation (reddening and itching), burns, and squamous papillomas
(warts) that appeared following acute or prolonged skin contact with coal-tar creosote. Coal-tar
creosote also induces phototoxicity of the skin (12). A phototoxic material makes the skin more
susceptible to damage such as sunburn and blisters upon exposure to light. Thus, the reported
burns are consistent with contact with creosote.
B. Health Outcome Data Evaluation
The State of Oregon maintains vital statistics (i.e., information about births and deaths). That information is collected at the county level. Oregon has neither a cancer nor a birth defects registry. No health studies on the workers at or the community around the site were found.
County-level data contain information about the whole county. Elevated death rates for a
community as small as that working at or living near the MB site would not affect county rates as
a whole. County data might provide information about trends in a community, but only a
community-specific analysis can truly attempt to answer whether cancer rates near the site are
elevated. If an elevated death rate is seen at the county level, we cannot prove its relation to the
site. Likewise, the absence of an elevated death rate does not mean that the site has had no effect
on the death rate in the community. For these reasons, ATSDR staff members did not examine
mortality rates.
C. Community Health Concerns Evaluation
Several health concerns were expressed at the ATSDR-sponsored public availability meeting in Portland on February 23, 1994. Those concerns are addressed in this section.
Chemical odors associated with breathing difficulties
There are no data on contaminant concentrations in air, so we do not know whether the odor people smelled was from chemicals from the site. We cannot determine whether people could get sick from the odor. We do know some of the health effects from inhalation of creosote and associated chemicals found on the site. Please refer to the Creosote, phenol, cresol, and polycyclic aromatic hydrocarbons (PAHs), Nearby residents discussion in the Toxicologic Evaluation section above. Breathing difficulties are consistent with exposure to site-related contaminants, but are also non-specific symptoms commonly experienced by individuals with no known exposures to hazardous waste.
Cancer
As discussed in the Toxicologic Evaluation section above, cancer occurs in the lifetime of one in three people (8). It is very difficult for scientists to determine who will get cancer. Further, if someone gets cancer, scientists and physicians typically cannot know the cause of the person's cancer. We do know, however, that some site-related chemicals are carcinogens; at sufficiently high doses, they are capable of causing specific cancers. Arsenic is a known human carcinogen; pentachlorophenol, dioxin, and creosote (as well as one of its parts, the polycyclic aromatic hydrocarbons) are probably human carcinogens.
Plant workers were exposed to carcinogens at levels of public health concern. We estimate a low to moderate increased cancer risk for workers exposed to arsenic, PCP, dioxin and PAHs through incidental soil ingestion. Additional exposure through inhalation or skin contact with those contaminants could increase the cancer risk.
We do not know to what chemicals or at what concentrations nearby residents were or are being exposed by breathing the air.
Lung Spots
Lung spots is a general descriptive term and is not actually a disease. A resident who lived near the site reported that the physician took a chest X-ray, which showed a spot. Although the person said he did not smoke, second-hand smoke from cigarettes might contribute to spot formation. There are additional conditions that can cause spots in the lungs, including a common cold complicated by pneumonia, other bacterial or viral infections, or the presence of manufactured fibers. Without substantive specific information about the spots, we cannot give any opinion about their possible cause.
Chronic bronchitis and lung tissue damage
We have no information about contaminant levels in the air near the site or about length of exposure. It is not possible to determine whether bronchitis and lung tissue damage would be expected in nearby residents. Concerned individuals should discuss potential chemical exposures when consulting their physicians.
Chronic bronchitis is among the most common conditions afflicting modern populations (16). Chronic bronchitis results from prolonged irritation of the bronchial membrane and causes coughing and excessive secretion of mucus for extended periods. By far the most common cause of chronic bronchitis is cigarette smoking, but air pollution and industrial fumes and dust irritation are also important irritants (17). Hereditary background can also play an important role (16). Chemicals used at the plant are respiratory irritants in people and animals and, at sufficient levels for sufficient amounts of time, have caused bronchitis and lung tissue damage in animals.
Safety of produce harvested from Sauvies Island
Sauvies Island is approximately 1½ miles downstream from the site. ATSDR staff members believe that contaminants originating from the site would be sufficiently diluted after entering the river and traveling 1½ miles to pose no hazard from ingested island produce that is irrigated with river water.
Burns to skin exposed to sediments
Youngsters reportedly received burns when playing in the river at the edge of the site. Sampling of river sediment found chemicals that are also found in creosote. The children's burns are consistent with contact with creosote. Please refer to the Creosote, phenol, cresol, and polycyclic aromatic hydrocarbons (PAHs), Historical wading exposure discussion in the Toxicologic Evaluation section.
Next Section
Table of Contents
