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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 wasconducted for surface soils, sediment, crayfish, and fish (Large Scale Sucker).

Those sampling data and supporting site-related information suggest that contaminantsassociated with wood treatment have been released to on-site soils, groundwater, and storm waterrunoff. 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, butsampling information is not available for confirmation. Citizens' concerns about odor alsosuggest releases, but sampling information is not available for confirmation. This sectionidentifies contaminants ATSDR representatives have selected for evaluation in later sections ofthis public health assessment to determine whether exposure to them has public healthsignificance. However, ATSDR's identification of contaminants here does not imply that humanexposure has occurred or that exposure would actually result in adverse health effects.

Contaminant selection considered the following factors:

  • Concentrations of contaminants in media.
  • Sample locations, field data quality, and laboratory data quality.
  • Relationship of concentrations to ATSDR's public health assessment comparison values; the absence of valid comparison values.
  • Community health concerns.

ATSDR's (EPA's) 1991 Toxic Chemical Release Inventory (TRI) (7), a database that containsinformation about annual releases of toxic chemicals to the environment, shows(1) approximately 80,000 pounds (total) of airborne releases of volatile organic compounds andgases were reported by three industrial facilities located between one-fourth of a mile and 1 milefrom the site and (2) another 113,000 pounds (total) reported by two facilities located between 1and 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 arenot addressed further in this section of the assessment.

The specific contaminants selected to be addressed further in the public health assessment arelisted in data tables organized according to the media in which they were found (Tables 1through 8 in Appendix B). Those tables include, where available, the public health assessmentcomparison values ATSDR used for selection. Environmental Media Evaluation Guides(EMEGs) are estimated comparison concentrations that are based on health effects informationdetermined by ATSDR for its Toxicological Profiles for specific chemicals. Cancer RiskEvaluation Guides (CREGs) are estimated comparison concentrations for specific chemicalsbased on an excess cancer rate of one in a million persons and are calculated using EPA's cancerslope factors. Reference Dose Media Evaluation Guide (RMEG) comparison concentrations arebased on EPA's estimate of the daily dose below which exposure to a contaminant is unlikely tocause adverse non-cancer health effects. Proposed Maximum Contaminant Levels (PMCLs)represent EPA's proposed drinking water contaminant concentrations considered protective ofpublic 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 familyof 210 structurally related chemical compounds. The PCDDs and PCDFs reported for samplestaken for this site are predominantly low-potency compounds (e.g., the octa and heptacompounds); 2,3,7,8 tetrachlorodibenzo-p-dioxin, the most potent of the compounds, occurs at amuch lower concentration than the rest. The EPA has developed a tentative methodology--theToxicity Equivalency Factor (TEF)--for reporting the cumulative concentrations of all PCDDsand 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-sitecontaminants; these are considered in developing the Public Health Implications section of thisassessment. This section summarizes from those tables the specific organic compound and metalfound at the highest concentrations. Identification of contaminants here and in the tables doesnot imply that human exposure has occurred or that exposure would actually result in adversehealth effects.

    Surface Soils (Table 1)

      4,900 parts per million (ppm)
      5,100 ppm

    Subsurface Soils (Table 2)

      23,000 ppm
      61,000 ppm

    Groundwater (Table 3)

      3,900,000 ppb (parts per billion)
      260,000 ppb

    NAPL*; below ground (Table 4)

      90,000,000 ppb
      not reported
      * nonaqueous-phase liquids; not readily soluble in water
    Storm Water (Table 5)
      1,700 ppb
      15,000 ppb (mean value)

B. Off-Site Contamination

Tables 6 through 8 (Appendix B) present the maximum documented values of the off-sitecontaminants; these are considered in developing the Public Health Implications section of thisassessment. This section summarizes from those tables the specific organic compound and metalfound at the highest concentrations. Identification of contaminants here and in the tables doesnot imply that human exposure has occurred or that exposure would actually result in adversehealth effects.

    Surface Soils (Table 6)
      1.3 ppm
      11 ppm (mean value)

    River Sediment (Table 7)

      3,500 ppm (estimated value)
      690 ppm
&nbsp &nbsp &nbsp &nbsp &nbsp &nbspRiver Water
Studies conducted to date have not included data on river water quality at the site location.

    Crayfish (Table 8)

      57 ppb
      15 ppm (mean value)

    Large Scale Sucker (Table 8)

      78 ppb (mean value
      7.4 ppm

C. Quality Assurance and Quality Control

Reference documents indicate that quality control protocols were followed for sampling andlaboratory analyses.

D. Physical and Other Hazards

ATSDR did not observe any substantive physical or other hazards associated with the site.


Discussion of specific human exposure pathways in this section does not imply that adversehealth effects are associated with them; health issues are discussed in the Public HealthImplications section. ATSDR identifies human exposure pathways by examining environmentaland human components that might lead to contact with contaminants. A pathway analysisconsiders 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 exposurepathways are those for which the five elements are evident, indicating that exposure to acontaminant has occurred in the past, is currently occurring, or will occur in the future. ATSDRregards people who come in contact with contamination as exposed; for example, people whodrink water known to be contaminated, or who reside in an area with contaminated air, or whowork or play in contaminted soil are considered exposed. Potential exposure pathways are thosefor which one or more of the elements is not clearly defined but through which exposure isplausible. Potential pathways indicate that exposure to a contaminant could have occurred in thepast, could be occurring now, or could occur in the future. Elements of completed and potentialexposure pathways are summarized in Tables 9 and 10 (Appendix B). Although the informationavailable is ample for identifying several specific completed and potential human exposurepathways, 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 orconcentrations on site (or off site) while MB operated, ATSDR's observations of active woodtreatment plants and awareness of treatment chemical potency lead the agency to conclude thatMB's workers were substantively exposed to volatilized chemicals and contaminated dustthrough 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 chemicalpotency lead the agency to conclude that MB's workers, during operations, were substantivelyexposed to contaminants associated with process chemicals and wastes and contaminants insurface soils (Table 1), principally through skin contact and incidental ingestion. Some of thecontaminants in process chemicals and wastes also are represented by sampling data obtained fornonaqueous-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 exposedto volatilized organic chemicals and probably some contaminated dust through inhalation whilethe plant operated. Sampling data are not available to identify the specific airborne contaminantsor their concentrations.

Other Completed Exposure Pathways

Because of the long-term potency of many of the contaminants, most of the exposures describedhere will continue until remediation is effected.

Soils: On Site

Evidence exists that trespassers occasionally breach the perimeter security fence intentionallyand enter the site. Trespass is believed to result in exposure to contaminants in surface soils nowand in the future (until remediation is effected), principally through skin contact and incidentalingestion. Table 1 identifies some of the on-site surface soil contaminants and their respectiveconcentrations.

Soils: Off Site

ATSDR believes residents and workers on nearby properties have been exposed, are now beingexposed, and will be exposed in the future to low levels of contaminants deposited on the groundby wind in off-site areas while the facility was in operation. Other urban sources are likely tohave contributed to the soil contamination. Exposures to contaminated surface soils occur offsite principally through skin contact and incidental ingestion. Table 6 identifies some of theoff-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, andODEQ representatives learned that two boys received skin burns on their legs while playing onthe adjacent downstream shoreline when the river level was low. Although the site securityfence extends into the river to prevent entry along the shoreline, ODEQ representatives note thatthe 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 beexposed 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 skincontact. Similar exposures can occur on the immediate downstream shoreline off site. Table 7identifies some river sediments contaminants and their respective concentrations. Contaminantsinclude those released from the site and possibly some released from additional sourcesupstream.

Crayfish and Fish: Off Site

The Oregon Health Division and Department of Fish and Wildlife have issued an advisorycautioning the public about commercial crayfish harvesting, and the shoreline area and paths tothe shore are posted. ODEQ is not aware of any recreational crayfishing activity. ODEQbelieves that the advisory has deterred commercial crayfishing in the immediate area, butcommercial crayfishing continues in downstream areas. This information indicates that peoplewho 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 tochemicals taken up by crayfish and fish. Table 8 identifies some of the contaminants andrespective concentrations present in tissue samples taken from crayfish and the large scalesucker. Contaminants include types released from the site and possibly from additional sourcesalong the river.

Surface Water: Off Site

ATSDR believes that shoreline users, recreational and commercial fishermen, water skiers, andswimmers in the immediate area have been exposed, are being exposed now, and will be exposedto contaminants released from the site in the future (until remediation is effected), principallythrough skin contact and incidental ingestion. Investigations conducted to date have not includedriver water quality data for the site vicinity. Table 1 (on-site surface soil), Table 3 (on-sitegroundwater), Table 4 (on-site below-ground NAPLs), and Table 5 (on-site storm water) identifysome of the contaminants released to the river; however, site-related concentrations in the riverare expected to be much lower than represented in the tables, which represent contaminants inon-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. ATSDRnotes there are considerable chemical processing and petroleum storage activities on the westbank of the river and elsewhere in the area; the EPA's Toxic Chemical Release Inventory showsthat some of those activities release volatile chemicals to the air. ATSDR's review of current siteconditions and periodic remedial activities suggests that chemicals on site continue to volatilizeat least to some limited extent, especially during warm weather, and some contaminated particlesare likely to be transported by wind. Although wood treatment operations have ceased, thereports of continuing odors indicate that people in the immediate area (including workers on siteand at nearby off-site businesses and also residents) are being exposed to airborne contaminantsthrough inhalation. The specific source or sources of periodic chemical odor exposure mightnever be clearly defined, and air-related exposure might not terminate after site cleanup iseffected.

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 precautionarymeasures are unexpectedly inadequate for the conditions encountered. Future users of the siteafter remediation is complete also have the potential to be exposed to subsurface contaminantsthrough 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 migrateupward through the protective soil cover, or if cracks develop in the soil cover, future site userscould be exposed to contaminants periodically through inhalation. Exposure, should it occurthrough these mechanisms, might not be substantive because the chemicals reported throughsampling are of low volatility.

Sediment: On Site and Off Site

Full remediation of site-related contaminated sediments along the shoreline and in the rivermight be difficult to achieve, and river currents conceivably could expose subsurfacecontaminants in the future. Therefore, ATSDR believes that persons using the shoreline afterremediation 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, whoconfirmed 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 Surveyand the Oregon Water Resources and found no wells recorded at locations that would likely beaffected by the site. No apparent past or present users of groundwater contaminated by sitereleases (Table 3) were disclosed, and future users of that resource are unlikely.


In this section, ATSDR discusses health effects of chemicals that people were exposed to on thesite, evaluates available health outcome data, and addresses specific community health concerns.

A. Toxicologic Evaluation

To determine whether people can get sick from exposure, ATSDR begins by estimating dailyexposure doses for each contaminant of concern by each route of exposure. We use informationabout levels of contaminants and about people's activities to estimate the exposure dose. Theestimated exposure dose is then compared to a Minimal Risk Level (MRL), which is an estimateof daily exposure to a contaminant below which noncancer disease is unlikely to occur. Todevelop the MRL, ATSDR relies on information from scientific studies of the effects of exposureto contaminants on people and animals. If an exposure dose exceeds an MRL, or if no MRL hasbeen 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 inadverse 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 effectsproduced in animals to predict the possibility of effects in people, as well as differences amongpeople.

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 thatexposure to some contaminants can increase the chances (or risk) of getting cancer. Even if aperson gets cancer, scientists and physicians typically cannot know the cause of the person'scancer. To determine whether exposure at this site might cause cancer, a numerical increase inthe risk of cancer is estimated using the estimated exposure dose and a cancer slope factordeveloped by the EPA specifically for each cancer-causing chemical.

Although potential and completed exposure pathways are described in detail in the PathwaysAnaylses section, pathways and the people involved with the pathways are reiterated in thissection to provide context for the reader. Adverse health effects of exposure to contaminants ofconcern are discussed. Health effects of exposure to some of the contaminants found at this siteare 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-potencycompounds) during the plant's operation. These exposures are believed to have been throughincidental ingestion (i.e., swallowing by accident during other swallowing activities) of soils onsite. These exposures were at levels of public health concern. Additional exposures which mayhave occurred through direct skin contact with the chemicals or inhalation of the vapors and dustin the air could increase the health risk. Workers could have inhaled additional chemicals thatoriginated off the site; several other industrial facilities in the site's vicinity have reported (in theEPA Toxic Release Chemical Inventory [TRI]) releasing unknown concentrations of chemicalsinto the air. A discussion of potential health effects associated with worker exposure to eachchemical or chemical class is presented later in this section.

Trespassers and visitors to the plant during its operation would have been exposed to the samechemicals to which the workers were exposed. Because of the short exposure time, it is highlyunlikely 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 reportedlyreceived skin burns, apparently from contact with hazardous chemicals. The site is believed tobe the source of the contamination. Other people might encounter chemicals along the shorelineat levels capable of burning the skin. Site-related chemicals that can burn the skin are discussedlater in this section.

People who eat contaminated fish and shellfish can be exposed to contaminants. Evaluation ofcontaminant levels in fish and shellfish indicate that, for people who subsist on crayfish orsuckers over a long time, health effects from exposure to polychlorinated dibenzodioxins anddibenzofurans might be expected. It is not known whether anyone ingests contaminated fish tothat extent. Those potential health effects are discussed later in this section.

Nearby residents and workers were exposed when they breathed contaminated air during theplant's operation. The site might not have been the only source of air contaminants. Othernearby facilities have reported releases. Because there is no available air data, those inhalationexposures cannot be evaluated. Residents have reported health effects that are known to beexperienced by individuals with no known exposure to hazardous waste, but are also consistentwith inhalation exposure to site-related contaminants. Site-related chemicals that can cause thosehealth effects are discussed later in this section.

Residents might also be exposed to airborne contaminants during remediation. Real-time airmonitoring would show whether airborne contaminants released by remedial activities would beat a level of health concern.

People who use the Willamette River near the site for recreation might be exposed by skincontact and incidental ingestion to any contamination that migrated into the river water. Studiesconducted to date have not included river water sampling. It is likely that site-relatedcontaminants are diluted enough in the water that there is no health threat to recreational waterusers.

Although the facility has been closed and fenced, remedial workers and people who trespass ontothe site or wander near the site at the river's edge can be exposed to contaminants by incidentallyingesting on-site soil and sediments in the river and at the river's edge. Because remedialworkers 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 theywill get sick this way. However, people who wander near the site at the river's edge mightexpose their skin to contaminated sediments. Contaminants in the sediment do not appear to beat levels that would cause any effects; however, in one case, two children who waded near thesite reportedly received skin injuries consistent with the type of damage exposure to site-relatedcontaminants can cause.

People who live or work nearby can incidentally ingest contaminants in soils on properties wherethey live or work. Results from several residential soil samples show that contaminant levels areso low that it is unlikely that anyone will get sick from incidentally ingesting soil. Limited soildata from adjacent industrial property also show that contaminant levels are so low that workersare unlikely to get sick from incidental soil ingestion; however, we do not have enough soilsample information to be reasonably sure that the contaminant concentrations found represent thetrue 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 contaminantscommonly found with pentachlorophenol at wood-treating facilities and have been found at thissite. Therefore, those chemical groups are included in this discussion. Health effects of eatingdioxin-contaminated fish are included in this discussion as well.

Coal-tar creosote is a complex mixture of more than 300 compounds, including polycyclicaromatic hydrocarbons (PAHs), phenol and cresols. PAHs have been found at this site. Thereare 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, becauseworkers 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 thesechemicals can injure the skin upon contact and the respiratory system upon inhalation, potentialhealth effects for people who wander along the shoreline and for people who live around the siteand breathe contaminated air are included in this discussion as well. There are no environmentaldata 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 is a naturally occurring element. Pure arsenic is a gray metal-like material; arsenic isusually found combined with such other elements as oxygen, chlorine, and sulfur. Arseniccombined with these elements is called inorganic arsenic. Inorganic arsenic is used as apreservative for wood to make it resist rot and decay; it is predominantly inorganic arsenic whichhas 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 arenumerous studies conducted on people who swallowed inorganic arsenic at doses similar to thoseATSDR 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 apattern of skin changes. This pattern includes a darkening of the skin and the appearance ofsmall warts or corns on the palms, soles, and torso. While these skin changes are not consideredto be a health concern in their own right, a small number of the corns might ultimately developinto skin cancer. Swallowing arsenic has also been reported to increase the risk of cancer in theliver, bladder, kidney, and lung. The Department of Health and Human Services (DHHS) andthe EPA have determined that arsenic causes cancer in humans. Arsenic in the soil at the site isat 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 ofthe stomach and intestines, with symptoms such as pain, nausea, vomiting and diarrhea; impairednerve 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 awood preservative and is released to the air by evaporation from treated wood surfaces. It entersthe soils as a result of spills. Polychlorinated dibenzo-p-dioxins and dibenzofurans, also calleddioxins and furans, are classes of compounds that do not occur naturally and are not intentionallymanufactured (except as reference standards for analytic laboratories). However, they can beinadvertently produced as impurities. Technical grade PCP usually contains dioxins and furansas impurities.

Plant workers

Plant workers were exposed to PCP and dioxins/furans through incidental ingestion, inhalationand 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 toxicequivalent concentration; the maximum dioxin/furan concentration was 0.38 ppm. Althoughthere are no data from which to estimate actual inhalation or skin exposure doses, workers atwood treatment facilities are known to inhale and take in through the skin significant levels ofPCP and dioxins/furans.

Because of PCP's frequent contamination with dioxins/furans, wood-treatment plant workerswho work with PCP are generally exposed to dioxins/furans as well. Studies conducted onwood-treatment workers exposed to PCP actually investigate health effects of exposure to PCPcontaminated with dioxins/furans (10).

Various studies of wood treatment workers exposed to PCP show that the blood, kidneys, andskin can be affected (10). Exposure was associated with aplastic anemia (defective functioningof the blood-forming cells), reduced kidney function, and skin and eye irritation. The lengthsand levels of exposure that cause harmful effects in people are not well defined. Studies in ratsand 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 skinproblem 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 isclassified as a probable human carcinogen because studies have shown an association betweeningesting pure PCP and cancer in mice; dioxins and furans are classified as probable humancarcinogens because studies have shown an association between dioxin ingestion and cancer inrats. The levels of PCP and dioxins/furan in the site's soil correspond to a low increased risk ofcancer for workers.

Crayfish and sucker eaters

ATSDR staff members estimated dioxin/furan exposure doses for people who eat contaminatedcrayfish and suckers on a regular basis. We assumed that people rely solely on crayfish andsuckers as their sole source of fish and shellfish (we assumed they ate between one and four sixounce meals of crayfish and/or suckers a month). The levels of dioxin/furans in crayfish andsuckers correspond to levels associated with a low increased risk of cancer for people whosubsist on crayfish and/or suckers for many years. In addition, although there have been nowell-substantiated reports of reproductive toxicity in people who ate dioxins/furans, studies inrats indicate that eating dioxin might cause spontaneous abortions (11). It is not known whetheranyone relies on crayfish and/or suckers harvested near the site as their sole source of fish andshellfish. For people who occasionally eat contaminated crayfish, no adverse health effects areexpected.

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, weremeasured in soil. Maximum concentrations of carcinogenic PAHs found on site were 420 ppmbenzo(a)anthracene; 210 ppm benzo(a)pyrene; 1,000 ppm benzofluoranthenes; 1,900 ppmchrysene; 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 workerexposure 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 skindescribe 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 thatinhalation of those compounds can irritate the respiratory tract (13,14). Creosote inhalationeffects are further discussed below in the Community Health Concerns Evaluation section.

Based on animal studies, the DHHS and the EPA have decided that the PAHsbenzo(a)anthracene, benzo(a)pyrene, benzofluoranthenes, chrysene, dibenz(a,h)anthracene andindeno(1,2,3-cd)pyrene probably cause cancer in people (15). Those PAHs have been found onsite. In laboratory experiments, they have caused tumors in animals when the animals breathedthem, ate them, or had long periods of skin contact with them. Studies of humans show thatindividuals exposed by breathing or skin contact for long periods to mixtures that contain PAHsand other compounds can also develop cancer. PAHs in the soil at the site are at levels whichcan 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 studiesshow inhalation of beechwood creosote, which has some of the same components as coal-tarcreosote, can cause irritation to the respiratory tract (12).

Phenol and cresols are constituents of coal-tar creosote. Animal studies of phenol exposure andhuman studies of cresols exposure indicate that those compounds can irritate the respiratory tractwhen inhaled (13,14). Although the results do not give a time frame, irritation probably beginswithin 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 thelungs was seen in animals exposed to cresols for one month (14).

Pentachlorophenol is another chemical commonly used at the site. There is very littleinformation on inhalation effects of pentachlorophenol; however, it appears to causeinflammation of the upper respiratory tract and bronchitis in people upon chronic, high-doseoccupational exposure in the presence of other chemicals (10).

Since we do not know what chemicals people were smelling or their concentrations, we cannotdetermine 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 inthe 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-tarcreosote also induces phototoxicity of the skin (12). A phototoxic material makes the skin moresusceptible to damage such as sunburn and blisters upon exposure to light. Thus, the reportedburns 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). Thatinformation is collected at the county level. Oregon has neither a cancer nor a birth defectsregistry. 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 acommunity as small as that working at or living near the MB site would not affect county rates asa whole. County data might provide information about trends in a community, but only acommunity-specific analysis can truly attempt to answer whether cancer rates near the site areelevated. If an elevated death rate is seen at the county level, we cannot prove its relation to thesite. Likewise, the absence of an elevated death rate does not mean that the site has had no effecton the death rate in the community. For these reasons, ATSDR staff members did not examinemortality rates.

C. Community Health Concerns Evaluation

Several health concerns were expressed at the ATSDR-sponsored public availability meeting inPortland 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 odorpeople smelled was from chemicals from the site. We cannot determine whether people couldget sick from the odor. We do know some of the health effects from inhalation of creosote andassociated chemicals found on the site. Please refer to the Creosote, phenol, cresol, andpolycyclic aromatic hydrocarbons (PAHs), Nearby residents discussion in the ToxicologicEvaluation section above. Breathing difficulties are consistent with exposure to site-relatedcontaminants, but are also non-specific symptoms commonly experienced by individuals with noknown exposures to hazardous waste.


As discussed in the Toxicologic Evaluation section above, cancer occurs in the lifetime of one inthree people (8). It is very difficult for scientists to determine who will get cancer. Further, ifsomeone gets cancer, scientists and physicians typically cannot know the cause of the person'scancer. We do know, however, that some site-related chemicals are carcinogens; at sufficientlyhigh 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 aromatichydrocarbons) are probably human carcinogens.

Plant workers were exposed to carcinogens at levels of public health concern. We estimate a lowto moderate increased cancer risk for workers exposed to arsenic, PCP, dioxin and PAHs throughincidental soil ingestion. Additional exposure through inhalation or skin contact with thosecontaminants could increase the cancer risk.

We do not know to what chemicals or at what concentrations nearby residents were or are beingexposed by breathing the air.

Lung Spots

Lung spots is a general descriptive term and is not actually a disease. A resident who lived nearthe site reported that the physician took a chest X-ray, which showed a spot. Although theperson said he did not smoke, second-hand smoke from cigarettes might contribute to spotformation. There are additional conditions that can cause spots in the lungs, including a commoncold complicated by pneumonia, other bacterial or viral infections, or the presence ofmanufactured fibers. Without substantive specific information about the spots, we cannot giveany 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 ofexposure. It is not possible to determine whether bronchitis and lung tissue damage would beexpected in nearby residents. Concerned individuals should discuss potential chemical exposureswhen 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 causescoughing and excessive secretion of mucus for extended periods. By far the most common causeof chronic bronchitis is cigarette smoking, but air pollution and industrial fumes and dustirritation 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 sufficientlevels 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 membersbelieve that contaminants originating from the site would be sufficiently diluted after entering theriver and traveling 1½ miles to pose no hazard from ingested island produce that is irrigated withriver water.

Burns to skin exposed to sediments

Youngsters reportedly received burns when playing in the river at the edge of the site. Samplingof river sediment found chemicals that are also found in creosote. The children's burns areconsistent with contact with creosote. Please refer to the Creosote, phenol, cresol, and polycyclicaromatic hydrocarbons (PAHs), Historical wading exposure discussion in the ToxicologicEvaluation section.

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