PUBLIC HEALTH ASSESSMENT
MONSANTO COMPANY/SOLUTIA INCORPORATED
[a/k/a ANNISTON PCB SITE (MONSANTO COMPANY)]
ANNISTON, CALHOUN COUNTY, ALABAMA
Figure 1. Solutia Owned Property
Figure 2. Areas Sampled Under the Second Consent Order
APPENDIX B: ASSUMPTIONS USED IN CALCULATING EXPOSURE DOSE ESTIMATES
| Location | Media | Potentially Exposed Population | Estimated Frequency of Exposure | Ingestion Rate |
| Area A | Subsurface soil | Adults | none | none |
| Children | none | none | ||
| Surface soil | Adults | 1 day a week | 50 mg/day | |
| Children | 1 day a week | 200 mg/day | ||
| Area B | Surface soil | Adults | 7 days a week | 50 mg/day |
| Children | 7 days a week | 200 mg/day | ||
| Children with pica behavior | 3 days a week | 8000 mg/day | ||
| Area BN | Subsurface soil | Workers | none | none |
| Surface soil | Workers | 5 days a week | 50 mg/day | |
| Area C | Surface soil | Adults | 7 days a week | 50 mg/day |
| Children | 7 days a week | 200 mg/day | ||
| Children with pica behavior | 3 days a week | 8000 mg/day | ||
| Sediment | Adults | 1 day a week | 50 mg/day | |
| Children | 1 day a week | 200 mg/day | ||
| Area CP | Surface soil | Workers | 5 days a week | 50 mg/day |
| Sediment | Workers | 1 day (intermittent exposure) | 50 mg/day | |
| Area D | Surface soil | Adults | 7 days a week | 50 mg/day |
| Children | 7 days a week | 200 mg/day | ||
| Children with pica behavior | 3 days a week | 8000 mg/day | ||
| Area E (Commercial) | Surface soil | Workers | 5 days a week | 50 mg/day |
| Sediment | Workers | 1 day (intermittent exposure) | 50 mg/day | |
| Area E (Residential) | Surface soil | Adults | 7 days a week | 50 mg/day |
| Children | 7 days a week | 200 mg/day | ||
| Children with pica behavior | 3 days a week | 8000 mg/day | ||
| Area GASCO | Surface soil | Workers | 1 day (intermittent exposure) | 50 mg/day |
| Area LF | Surface soil | Workers | 1 day (intermittent exposure) | 50 mg/day |
| Adults | 1 day (intermittent exposure) | 50 mg/day | ||
| Area MDN | Surface soil | Workers | 1 day (intermittent exposure) | 50 mg/day |
| Adults | 1 day (intermittent exposure) | 50 mg/day | ||
| Children | 1 day (intermittent exposure) | 200 mg/day | ||
| Area NP | Surface soil | Adults | 1 day a week | 50 mg/day |
| Children | 1 day a week | 200 mg/day | ||
| Area XE | Surface soil | Workers | 5 days a week | 50 mg/day |
| Trespasser | 1 day (intermittent exposure) | 50 mg/day | ||
| Line A | Subsurface soil | Adults | none | none |
| Children | none | none | ||
| Sediment | Adults | 1 day (intermittent exposure) | 50 mg/day | |
| Children | 1 day (intermittent exposure) | 200 mg/day |
Public health assessments are released in draft form to the public for comment. For this public health assessment, the required 30 day public comment period was doubled, allowing the public 60 days to submit comments. This appendix contains public comments in the order they were received and responses from ADPH/ATSDR.
Ms. Barnett once again did a super job in preparing this report and Ms. Browder was all too valuable! Ms. Barnett will be greatly missed. I would like to make my medical records available to the ATSDR as "so far" I have and still suffer from health effects.
Response: Thank you for the complements. Thank you also for offering medical records. On those occasions when ADPH and ATSDR reviewed medical records, we appreciate people who are willing to participate.
What about the people and property on Montrose Avenue? What are you going to do? Now!
Response: The people and property on Montrose Avenue were tested during an exposure investigation in 1995-1996. Because the exposure investigation showed that people were exposed to PCBs, ADPH recommended that those people relocate and/or allow cleanup to prevent further exposure. Unfortunately, a few people did not agree to allow their property to be remediated. They continue to be at risk for exposure. ADPH and ATSDR continue to recommend that steps be taken to stop exposure.
Will I need testing?
Response: ADPH is concerned about the many people who have not been tested for PCBs, and we all want more information about how PCB exposure might affect health. The tests are very expensive and ADPH has requested assistance to fund more work.
It's a little confusing to read and understand all the facts.
Response: Unfortunately, that comment is correct. Thank you for your honesty. There were different kinds of property sampled: residential, business, municipal, and utility. For each property, ADPH identified people who might go to the area and how they might come into contact with contaminated soil. ADPH regrets the confusion caused by our efforts to describe each location.
Probably no clear answers but it is not clear what health effects really are. Also, newer information regarding extensive testing. Would have liked a clearer map.
Response: The comment is correct, there are few clear answers on human health effects of PCB exposure. ATSDR has prepared a health consultation on the newer information. They have received comments on that report and are responding to the comments. ADPH regrets that details on the maps are not very clear, making them difficult to read.
The 5 ppm detection limit--who determined this? and how? Who regulates landfills? Need a health study to be done for Calhoun County. Since manufacture of PCBs discontinued and people continue to be exposed--remove landfill. What took so long for this study? There needs to be updated data--this report was done several years ago.
Response: The 5 ppm detection limit referred to in the report is for samples that were collected and analyzed quickly in the field by a field screening method. The field screening kit read the results of each sample as less than 5 ppm or greater than 5 ppm. Newer field screening kits currently being used in Anniston by the EPA have a lower detection limit.
The landfills are regulated by the Alabama Department of Environmental Management under the Resource Conservation and Recovery Act. Any decisions regarding the landfills, including removal, are currently under the authority of ADEM.
The samples evaluated in this public health assessment were collected and reported to ADPH in 1996. ADPH regrets that a shortage of workers delayed the completion of this public health assessment.
ATSDR wrote a health consultation on updated environmental and blood sampling. ATSDR has also written several other reports on environmental issues in Anniston including childhood exposure to PCBs, lead in soil, etc. Several of these reports were released for public comment.
TITLE
The use of the word "aliases" is inappropriate in a document of this type. In addition, the description of the site in the title is inaccurate and misidentifies the assessment area. The name of the owner of the site is Solutia Inc. The area which this assessment addresses is more properly denoted as near-site areas, rather than "Snow Creek Area." Snow Creek is the subject of Solutia's ongoing off-site RFI process and is not included in the area described in the present document. Solutia suggests that the title of the document be changed to the following: Public Health Assessment for Solutia Inc. (formerly known as the chemical businesses of Monsanto Company) Near-site Areas Anniston, Calhoun County, Alabama CERCLIS No. ALD 004 019 048
Response: The site name for this document is changed to Monsanto Company/Solutia Inc. The samples evaluated in this document were collected by Monsanto Company in 1996. The facility is now named Solutia Inc. ADPH will include both names in the title to reflect their involvement.
Background, Site Description and History
Page 1, second paragraph of section: The second sentence implies that the manufacture of polychlorinated biphenyls (PCBs) and other chemicals by Monsanto at the Anniston site only began after the purchase of Swann Chemical Company by Monsanto in 1935. In reality, those chemicals had been manufactured by Swann for several years at the time of the purchase, and, more correctly, Monsanto continued the manufacturing of those chemicals.
Response: Comment noted.
Page 2, first full sentence: The draft PHA mischaracterizes the relationship between Monsanto and Solutia Inc. (not Solutia, Incorporated as denoted in the document). On September 1, 1997, Monsanto spun off its former chemical businesses as Solutia Inc., which is a totally separate business entity.
Response: Comment noted.
Page 2, first full paragraph: Solutia believes the West End Landfill was used only until 1960, not 1961 as denoted in the document. Solutia suggests replacing "exchanged to" to "exchanged with" in the next-to-last line.
Response: The sentence addressing the property exchange has been rewritten.
Page 2, second full paragraph: In this paragraph and elsewhere, the PHA refers to the drainage ditch which ran through the area east of the Solutia facility as the "Eastern Drainage Ditch" and, alternatively, as the "East Drainage Ditch." Solutia suggests that a consistent name be used and that "East Drainage Ditch" is more consistent with previous documents submitted to the Alabama Department of Environmental Management (ADEM) and the Alabama Department of Public Health (ADPH).
Response: The wording has been changed to "East Drainage Ditch."
Previous Investigations, South Landfill
Page 2, last paragraph: The wording of the last sentence, "closing the ditches with PCB contaminated sediment," is subject to misinterpretation. Solutia suggests that a more complete description of the remediation process would be appropriate. The East Drainage Ditch was lined with a geotextile liner and then covered with up to 6 feet of clean soil and an impermeable geomembrane liner. Tributary ditches were also lined with a geotextile liner and were filled with clean soil. All areas, including the ditches, were then covered with a minimum of 14 inches of clean soil and were seeded.
Response: Comment noted.
West End Landfill
Page 3, first paragraph: In this paragraph and elsewhere, the PHA refers to "storm water," "storm-water," and "stormwater." Solutia suggests consistent terminology ("storm water") be used.
Response: The wording has been changed to storm water.
In the fourth line from the end of the paragraph, "line" should read "liner."
Response: The word has been changed to liner.
Off-site Areas Sampled
Page 3, second paragraph of this section: In the third line, "Clydesdale Road" should read "Clydesdale Avenue." The penultimate sentence mischaracterizes Solutia's current activity with regard to purchase of property. Solutia is no longer actively negotiating to purchase either residential or commercial properties, although Solutia would consider the purchase of properties in the original Property Purchase Programs areas, if the owners wished to reconsider participating in the Program. In addition, the cited reference for that sentence, "[2]," does not appear to be correct. Solutia suggests deleting the sentence and reference.
Response: The paragraph has been revised to clarify and update information.
Page 5, first paragraph after the list of areas: The cited reference at the end of the paragraph, "[2]," does not appear to be correct. The correct reference would appear to be number 7 on the list on Page 28.
Response: Because references 2 and 7 are both appropriate to cover the series of actions listed, reference 7 has been added.
Alabama Department of Public Health Involvement
Page 7, first paragraph, first line: Solutia's proper corporate name is "Solutia Inc.", not "Solutia Company." At the time of the contact, the representatives would have been employees of Monsanto.
Response: The sentence has been corrected.
Page 7, second paragraph: The reference cited at the end of the paragraph, "[6]," does not appear to be correct. The correct reference may be number 4 on Page 28.
Response: Reference 6 has been changed to 1 and 4 as both are appropriate.
Page 7, fourth paragraph: There are several citations to reference [6] in this paragraph, none of which appears to be correct. The correct reference may be number 4 on Page 28.
Response: The reference has been changed to 4.
Page 7, fifth paragraph: Solutia suggests replacing "an exam" with "a medical examination" in the first sentence and replacing "PCB exam" with "medical examination" in the second sentence.
Response: The paragraph has been rewritten to clarify activities conducted by the University of Alabama at Birmingham, Occupational and Environmental Medicine Clinic.
Page 8, first paragraph: The reference cited at the end of the paragraph, "[6]," does not appear to be correct. The correct reference may be number 4 on Page 28.
Response: The reference has been changed to 4.
Page 8, second paragraph: This paragraph somewhat mischaracterizes the timing and nature of Monsanto Company's Property Purchase Program. The Property Purchase Program was instituted in October of 1995 to acquire residential properties in the area east of the Anniston facility in order to facilitate management and control of the PCB impacted soils and sediments in the area. This Program was instituted prior to the ADPH health consultations. The area to which the Program applied was generally defined by the presence of PCBs in soils and sediments above the screening level of the immunoassay tests being used to determine the extent of PCB-impacted soils. Subsequent to the signing of Consent Order No. 96-054-CHW between Monsanto and ADEM, Monsanto extended the Property Purchase Program to Montrose Avenue, which is east of and upgradient of the original area. Many of the property owners on Montrose Avenue agreed to participate in the Program. None of the properties purchased was "in the immediate vicinity of Snow Creek."
Response: The paragraph has been rewritten to reflect the expanded area.
Discussion, Polychlorinated Biphenyls (PCBs)
Page 8, first paragraph of this section: Although natural sources of PCBs are probably minor, there are literature reports of naturally-occurring PCBs.
Response: Comment noted.
Page 8, third paragraph of this section, continuing to Page 9: Solutia believes this paragraph mischaracterizes the amount and nature of the scientific and medical literature concerning PCBs. It is not correct that the information available on the human health implications of exposure to PCBs is "very limited." That literature is voluminous, and several excellent reviews have also been published, for example, "Polychlorinated Biphenyl Exposure and Human Disease," James, R. C., et al., J. Occup. Med., 1993, 35(2):136-148. Much of the literature has also been summarized in ATSDR's Toxicological Profile for Polychlorinated Biphenyls, which is cited as reference 9 on Page 29 of the draft PHA. Although the draft PHA properly notes some of the limitations of the various publications describing the potential human health effects of PCBs, it does not give appropriate weight to the strengths of those same studies, including the fact that the subjects of most of those studies were occupationally exposed persons whose exposures were significantly higher than those of most environmentally exposed persons. As Dr. James observed in the abstract of the paper cited above, ". . . [T]he weight of evidence suggests the only adverse health effects attributable to high, occupational PCB exposures are dermal . . . [T]he collective occupational experience with PCB fluids provides no evidence for adverse PCB effects on any other organ systems."
Response: The public health assessment is based on a balanced public health assessment of the literature. No changes are necessary.
Page 9, first full paragraph: Although this paragraph correctly notes that the studies discussed therein are studies of laboratory animals and wildlife, the paragraph could be incorrectly interpreted. Solutia suggests adding the phrase "in animals" after the words "toxic effects" in the second sentence and at the end of the third sentence.
Response: It is clear that animal studies are the subject of the entire paragraph. No changes are necessary.
Page 9, second full paragraph: This paragraph also mischaracterizes the results of the studies of persons exposed occupationally to PCBs. The paper by James et al., which was cited above, provides a thorough review of the studies of such workers. The only organ system for which the weight of the evidence suggests the potential for an adverse human health effect is the skin. The other systems mentioned in this paragraph of the PHA are only reported in isolated studies, if at all. Several studies do report transient elevations in levels of certain liver enzymes; however, the elevations are not clinically significant and are inconsistent with regard to the particular enzymes potentially affected. The sporadic reports of possible effects on other organ systems do not meet well established criteria for causation and cannot be relied upon to suggest that exposure to PCBs is associated with adverse effects on those systems. Solutia suggests the following wording: "Studies of laboratory animals have suggested that there is a potential for effects on the thyroid gland, the liver, the skin, the eyes, the blood, and the immune system. However, clinical studies of occupationally exposed populations have found that the only adverse health effects attributable to high occupational exposures to PCBs are dermal (e.g., chloracne)."
Response: The public health assessment is based on a balanced evaluation of the relationship between animal studies and human health. No changes are necessary.
Page 9, third full paragraph: While this paragraph correctly notes that the isolated reports of associations of occupational exposure to PCBs with cancer in a variety of physiological sites " . . . have not been observed consistently across studies," Solutia feels the weight of the evidence of those studies should be conveyed in a more positive manner. As Dr. Renate Kimbrough observed in a 1995 review, Polychlorinated Biphenyls (PCBs) and Human Health: An Update, "These studies (in the reviewer's opinion) have not provided any convincing evidence that PCBs are human carcinogens." (Emphasis added.) Kimbrough, R. D., Crit. Rev. Toxicol., 1995, 25(2):133-163. Ironically, while this paragraph of the PHA cites Dr. Kimbrough's recently published study of the largest group of electrical workers exposed to PCBs to summarize the sporadic findings from other studies, it does not include the results of that study itself. The abstract of Dr. Kimbrough's 1999 study concludes, "None of the previously reported specific excesses in cancer mortality were seen. This is the largest cohort of male and female workers exposed to PCBs. The lack of any significant elevations in the site-specific cancer mortality of the production workers adds important information about the human health effects of PCBs." Kimbrough, R. D., et al., J. Occup. Environ. Med., 1999, 41(3):161-171.
Response: ADPH's balanced public health assessment of the carcinogenicity of PCBs is based on a weight of evidence approach; it is not based on limited studies. The public health assessment text further states that PCBs have been designated as probable carcinogens or reasonably anticipated to be carcinogens by the Department of Health and Human Services, the International Agency for Research on Cancer, and EPA. No changes are necessary.
Environmental Contamination and Exposure Pathways
Page 10, third paragraph: It is unclear why ADPH/ATSDR has chosen ATSDR's Cancer Risk Evaluation Guide (CREG) as the comparison value for non-cancerous health effects. The use of this conservative CREG in conjunction with other conservative assumptions used to evaluate some of the areas addressed by this document results in overly restrictive evaluations.
Response: A comparison value is used as a screening tool. Conservative screening tools are desired and needed in order to be protective of public health. We disagree that the evaluations contained in this PHA are overly restrictive.
Page 10, fourth paragraph: While Solutia understands the need to deal appropriately with the large number of soil PCB concentrations that were below the screening level of 5 ppm, the uniform application of one-half of the detection limit (2.5 ppm) to those values almost certainly exaggerated the exposure estimates in many of the areas evaluated, especially those where most of the samples had no PCBs detected above the screening level. Solutia recommends recalculating the values using zero ppm (0 ppm) as the surrogate value and reporting both results in the PHA. This calculation would provide a range of average PCB values and would allow more appropriate ranges of estimated doses. Solutia also questions the use of average PCB soil levels to estimate "exposure doses" in the evaluated areas without some analysis of distribution of soil level results. It is not possible to determine by examining the data as presented in the PHA whether the average value is a fair representation of the distribution of results or whether one or two relatively high values biased the average.
Response: Any sample result that is reported to be below the 5.0 ppm detection limit represents an unknown quantity that could actually be any concentration between 0.0 ppm and 4.9 ppm. By assigning these samples a value of 2.5 ppm, the average concentration can be calculated with the least potential for either underestimating or overestimating the unknown. No changes are necessary.
Page 11, Tables 1,2, and 3: There appear to be errors in at least some of the average concentrations reported on these tables. In Table 3, for example, the average concentration for Area A and Line A are the same as the highest value reported for the concentration range, which cannot be the case. Solutia suggests confirming the calculations of averages using 2.5 ppm for the "non-detects," repeating and reporting the average concentrations using 0 ppm for the "non-detects," and providing some information about the distribution of the values in the concentration ranges.
Response: The average concentrations for subsurface soil at Area A and Line A were recalculated assigning the value of 2.5 ppm for the non-detects. The corrected averages have been entered into Table 3.
Determining Public Health Implications
Page 12, second paragraph, first sentence: Insert "upper bound" between "theoretical" and "cancer risk" to clarify that the cancer risk estimates calculated using the EPA cancer slope factor for PCBs are upper bound risk estimates. The paragraph should also indicate that according to the EPA the true risk could be as low as zero.
Response: Appropriate language has been added to the PHA.
Page 12, fourth paragraph: This paragraph should also include a statement that the risk estimates calculated using the EPA cancer slope factor are upper bound risk estimates and that the true risk could be as low as zero. Solutia notes that the discussion of "background" cancer risks provides appropriate perspective.
Response: Similar language was inserted in paragraph 2 as requested in the comment immediately before this one. No changes were made to paragraph 4 in response to this comment.
Page 13, first paragraph, fifth sentence: This sentence provides an example of how the decision to use 2.5 ppm as the default concentration when PCBs were not detected above the screening level of 5 ppm could result in an overly conservative estimation of "exposure dose." If, in fact, the use of 2.5 ppm as the surrogate for non-detection exaggerated the true level of PCBs in a given area, the "estimated exposure dose" would also be exaggerated, leading eventually to an exaggerated calculation of estimated risk. Solutia again suggests repeating the calculations of average concentrations using zero ppm (0 ppm) as the surrogate for non-detection and reporting both values in the PHA.
Response: Any sample result that is reported to be below the 5.0 ppm detection limit represents an unknown quantity that could actually be any concentration between 0.0 ppm and 4.9 ppm. By assigning these samples a value of 2.5 ppm, the average concentration can be calculated with the least potential for either underestimating or overestimating the unknown. No changes are necessary.
Past, Present, and Potential Future Exposures (Area LF)
Page 14, first paragraph of this section: In the sixth line of this paragraph, the second occurrence of the word "workers" should be deleted. The infinitive phrase should read " . . . to dispose of waste and . . . "
Response: The duplicate word has been deleted.
Area NP
Page 14, second paragraph of this section: Solutia suggests changing "To reduce . . . " to "To eliminate. . ."
Response: The description of actions taken does not support the suggested word substitution.
Past, Present, and Potential Future Exposures (Area NP)
Page 14, second paragraph of section, continuing to Page 15: The discussion of the potential for adverse non-cancerous health effects for preschool children mischaracterizes the animal and human scientific literature on these potential effects, even if one assumes the validity of the studies. There are several issues which need to be considered before ADPH and ATSDR suggest, as they do in this document, that neurobehavioral effects could have resulted from exposure to PCBs in this area or in areas B, C, D, and E below, for which the same characterization is presented. Reviews of the studies of potential neurobehavioral effects in humans associated with exposure to PCBs and other chemicals by Dr. Susan Schantz (Schantz, S. L., Neurotoxicol. Teratol., 1996, 18(3):217-227) and Dr. Richard Seegal (Seegal, R. F., Crit. Rev. Toxicol., 1996, 26(6):709-737) discussed in great detail the various criticisms of those studies, noted the small magnitude of the changes noted, and concluded that the studies, taken as a whole, are inconclusive. Further, even if one assumes that the various studies reviewed by Schantz and Seegal do have some validity, the subtle effects were reported to be associated with prenatal exposure to the chemicals, not to postnatal exposures, such as incidental ingestion of surface soil. Finally, many of the animal studies on which the agencies seem to rely for the description of potential non-cancerous effects were carried out at dosage levels much higher than those associated with potential incidental ingestion of surface soils. Solutia believes the suggestion that neurobehavioral effects could have resulted from exposures to soil in Area NP and other areas is not supported by the scientific literature.
Response: The reports cited in the comment point out the uncertainty and somewhat confusing nature of our understanding of the health effects associated with PCB exposures. Part of the difficulty of obtaining definitive evidence is related to the low dose exposures encountered in environmental scenarios, and variations in individual responses to PCB exposures. These factors hinder the ability to produce a definitive assessment for health effects an individual may experience related to PCB exposures.
Despite this confusion, numerous, more recent reports of laboratory and epidemiological investigations have added to the weight of evidence indicating that concerns over environmental exposures to PCBs are warranted (for general reviews see: J. P. Giesy and K. Kannan. 1998 Critical. Rev. Toxicol. 28:511-569; L. J. Fischer, R. Seegal, p. Ganey, I. Pessah, and P. Kodavanti. 1998. Toxicol. Sci. 41:49-61). It must be noted that although some investigators conclude that the published reports describe subtle effects of questionable consequence, others consider the results "adverse" responses. Some investigators conclude that the evidence from animal experiments leads to strong suspicions that similar effects may occur in humans. Included in these documented and suspected responses to PCBs are neurodevelopmental effects (A. Brouwer, M. Longnecker, L. Birnbaum, J. Cogliano, P. Kostyaiak, S. Schantz, and G. Winneke. 1999. Envir.. Health Perspect. 107:639-649;) and altered thyroid homeostasis (N,. Osius, W. Karmaus, H. Kruse, J. Witten. 1999. Envir. Health Perspect. 107:843-849; S. Poprterfield, 2000. Envir.. Health Perspect. 108:433-438). Of importance are reports indicating that pre-and postnatal exposures to PCBs may be of particular concern (A. Brouwer, M. Longnecker, L. Birnbaum, J. Cogliano, P. Kostyaiak, S. Schantz, and G. Winneke. 1999. Envir.. Health Perspect. 107:639-649).
Based on a limited review of the newer evidence, ADPH and ATSDR believe that it is reasonable to suspect that exposures to PCBs can induce a variety of responses in both animals and humans, and that some of those responses may occur as a result of exposures to environmental PCBs.
Residential Areas, Area A
Page 15, first paragraph of this section: In the third line from the bottom of the paragraph, the proper name of the church is the First Missionary Baptist Church (not "Mission").
Response: The name of the church has been corrected.
Page 15, second paragraph, second sentence: It should be noted that the "contaminated soil" which was removed contained PCBs at far less than the 50 ppm regulatory limit for TSCA (Toxic Substance Control Act)-regulated wastes.
Response: The PCB concentrations are listed in the previous paragraph. No changes are necessary.
Area B
Page 16, second paragraph of this section: In the penultimate sentence, it is stated that "Solutia was not provided access. It would be more correct to note that Solutia was refused access to the property to remediate the isolated spot where PCBs were present above the screening level but well below the 50 ppm regulatory limit.
Response: One word of the sentence was changed.
Past, Present, and Potential Future Exposures (Area B)
Page 16, first paragraph of this section, third sentence: It is an exaggeration to state that " . . . a current completed pathway of exposure exists . . . " because the low levels of PCBs are only present in an isolated spot in the yard, not in the whole yard. The isolated nature of this spot of soil containing 9 ppm of PCBs should be noted specifically.
Response: The public health assessment correctly identifies a completed exposure pathway. Subsequent to identifying pathways of exposure, PCB concentrations and frequency of contact are evaluated to calculate dose. No change is necessary.
Page 16, second paragraph of this section, continuing to Page 17: Please see comment for Past, Present, and Potential Future Exposures (Area NP), Page 14.
Response: The reports cited in the comment point out the uncertainty and somewhat confusing nature of our understanding of the health effects associated with PCB exposures. Part of the difficulty of obtaining definitive evidence is related to the low dose exposures encountered in environmental scenarios, and variations in individual responses to PCB exposures. These factors hinder the ability to produce a definitive assessment for health effects an individual may experience related to PCB exposures.
Despite this confusion, numerous, more recent reports of laboratory and epidemiological investigations have added to the weight of evidence indicating that concerns over environmental exposures to PCBs are warranted ( for general reviews see: J. P. Giesy and K. Kannan. 1998 Critical. Rev. Toxicol. 28:511-569; L. J. Fischer, R. Seegal, p. Ganey, I. Pessah, and P. Kodavanti. 1998. Toxicol. Sci. 41:49-61). It must be noted that although some investigators conclude that the published reports describe subtle effects of questionable consequence, others consider the results "adverse" responses. Some investigators conclude that the evidence from animal experiments leads to strong suspicions that similar effects may occur in humans. Included in these documented and suspected responses to PCBs are neurodevelopmental effects (A. Brouwer, M. Longnecker, L. Birnbaum, J. Cogliano, P. Kostyaiak, S. Schantz, and G. Winneke. 1999. Envir.. Health Perspect. 107:639-649;) and altered thyroid homeostasis (N,. Osius, W. Karmaus, H. Kruse, J. Witten. 1999. Envir. Health Perspect. 107:843-849; S. Poprterfield, 2000. Envir.. Health Perspect. 108:433-438). Of importance are reports indicating that pre-and postnatal exposures to PCBs may be of particular concern (A. Brouwer, M. Longnecker, L. Birnbaum, J. Cogliano, P. Kostyaiak, S. Schantz, and G. Winneke. 1999. Envir.. Health Perspect. 107:639-649).
Based on a limited review of the newer evidence, ADPH and ATSDR believe that it is reasonable to suspect that exposures to PCBs can induce a variety of responses in both animals and humans, and that some of those responses may occur as a result of exposures to environmental PCBs.
Area C
Page 17, second paragraph of this section, second sentence: This sentence should be modified to note that as part of the remediation process Solutia placed a minimum of 14 inches of clean soil on top of the geosynthetic liner and seeded the property.
Response: The sentence was based on the author's personal communication with Solutia's Manager of Remedial Projects rather than on a document which can be researched to verify the information. The author has left ADPH and the information offered in the comment does not materially change the public health assessment; therefore, the wording will not be changed.
Past, Present, and Potential Future Exposures (Area Q
Page 17, second paragraph of this section continuing to Page 18, first full paragraph: Please see comment for Past, Present, and Potential Future Exposures (Area NP), Page 14. Also, the scientific literature does not support the statement that " . . .immunological effects have been observed in human studies. . . "
Response: The reports cited in the comment point out the uncertainty and somewhat confusing nature of our understanding of the health effects associated with PCB exposures. Part of the difficulty of obtaining definitive evidence is related to the low dose exposures encountered in environmental scenarios, and variations in individual responses to PCB exposures. These factors hinder the ability to produce a definitive assessment for health effects an individual may experience related to PCB exposures.
Despite this confusion, numerous, more recent reports of laboratory and epidemiological investigations have added to the weight of evidence indicating that concerns over environmental exposures to PCBs are warranted ( for general reviews see: J. P. Giesy and K. Kannan. 1998 Critical. Rev. Toxicol. 28:511-569; L. J. Fischer, R. Seegal, p. Ganey, I. Pessah, and P. Kodavanti. 1998. Toxicol. Sci. 41:49-61). It must be noted that although some investigators conclude that the published reports describe subtle effects of questionable consequence, others consider the results "adverse" responses. Some investigators conclude that the evidence from animal experiments leads to strong suspicions that similar effects may occur in humans. Included in these documented and suspected responses to PCBs are neurodevelopmental effects (A. Brouwer, M. Longnecker, L. Birnbaum, J. Cogliano, P. Kostyaiak, S. Schantz, and G. Winneke. 1999. Envir.. Health Perspect. 107:639-649;) and altered thyroid homeostasis (N,. Osius, W. Karmaus, H. Kruse, J. Witten. 1999. Envir. Health Perspect. 107:843-849; S. Poprterfield, 2000. Envir.. Health Perspect. 108:433-438). Of importance are reports indicating that pre-and postnatal exposures to PCBs may be of particular concern (A. Brouwer, M. Longnecker, L. Birnbaum, J. Cogliano, P. Kostyaiak, S. Schantz, and G. Winneke. 1999. Envir.. Health Perspect. 107:639-649).
Based on a limited review of the newer evidence, ADPH and ATSDR believe that it is reasonable to suspect that exposures to PCBs can induce a variety of responses in both animals and humans, and that some of those responses may occur as a result of exposures to environmental PCBs.
Area D
Page 18, first paragraph of this section: In the penultimate sentence, it is stated that "Solutia was not provided access. It would be more correct to note that Solutia was refused access to the property to remediate the isolated spot where PCBs were present above the screening level but well below the 50 ppm regulatory limit.
Response: One word of the sentence was changed.
Past, Present, and Potential Future Exposures (Area D)
Page 18, second paragraph of this section and Page 19, first paragraph: Please see comment for Past, Present, and Potential Future Exposures (Area NP), Page 14. Also, the scientific literature does not support the statement that " . . .immunological effects have been observed in human studies. . . "
Response: The reports cited in the comment point out the uncertainty and somewhat confusing nature of our understanding of the health effects associated with PCB exposures. Part of the difficulty of obtaining definitive evidence is related to the low dose exposures encountered in environmental scenarios, and variations in individual responses to PCB exposures. These factors hinder the ability to produce a definitive assessment for health effects an individual may experience related to PCB exposures.
Despite this confusion, numerous, more recent reports of laboratory and epidemiological investigations have added to the weight of evidence indicating that concerns over environmental exposures to PCBs are warranted ( for general reviews see: J. P. Giesy and K. Kannan. 1998 Critical. Rev. Toxicol. 28:511-569; L. J. Fischer, R. Seegal, p. Ganey, I. Pessah, and P. Kodavanti. 1998. Toxicol. Sci. 41:49-61). It must be noted that although some investigators conclude that the published reports describe subtle effects of questionable consequence, others consider the results "adverse" responses. Some investigators conclude that the evidence from animal experiments leads to strong suspicions that similar effects may occur in humans. Included in these documented and suspected responses to PCBs are neurodevelopmental effects (A. Brouwer, M. Longnecker, L. Birnbaum, J. Cogliano, P. Kostyaiak, S. Schantz, and G. Winneke. 1999. Envir.. Health Perspect. 107:639-649;) and altered thyroid homeostasis (N,. Osius, W. Karmaus, H. Kruse, J. Witten. 1999. Envir. Health Perspect. 107:843-849; S. Poprterfield, 2000. Envir.. Health Perspect. 108:433-438). Of importance are reports indicating that pre-and postnatal exposures to PCBs may be of particular concern (A. Brouwer, M. Longnecker, L. Birnbaum, J. Cogliano, P. Kostyaiak, S. Schantz, and G. Winneke. 1999. Envir.. Health Perspect. 107:639-649).
Based on a limited review of the newer evidence, ADPH and ATSDR believe that it is reasonable to suspect that exposures to PCBs can induce a variety of responses in both animals and humans, and that some of those responses may occur as a result of exposures to environmental PCBs.
Area E - Residential
Page 19, second paragraph of this section, second sentence: The wording of this sentence is somewhat misleading. It is clearer to say, "Solutia purchased the properties in this area and removed all of the structures. Solutia restricted access to the area with a fence."
Response: The sentence has been clarified.
Past, Present, and Potential Future Exposures (Area E-Residential)
Page 19, second paragraph of this section and third paragraph of this section continuing to Page 20: Please see comment for Past, Present, and Potential Future Exposures (Area NP), Page 14. Also, the scientific literature does not support the statement that immunological effects have been observed in human studies. . . "
Response: The reports cited in the comment point out the uncertainty and somewhat confusing nature of our understanding of the health effects associated with PCB exposures. Part of the difficulty of obtaining definitive evidence is related to the low dose exposures encountered in environmental scenarios, and variations in individual responses to PCB exposures. These factors hinder the ability to produce a definitive assessment for health effects an individual may experience related to PCB exposures.
Despite this confusion, numerous, more recent reports of laboratory and epidemiological investigations have added to the weight of evidence indicating that concerns over environmental exposures to PCBs are warranted ( for general reviews see: J. P. Giesy and K. Kannan. 1998 Critical. Rev. Toxicol. 28:511-569; L. J. Fischer, R. Seegal, p. Ganey, I. Pessah, and P. Kodavanti. 1998. Toxicol. Sci. 41:49-61). It must be noted that although some investigators conclude that the published reports describe subtle effects of questionable consequence, others consider the results "adverse" responses. Some investigators conclude that the evidence from animal experiments leads to strong suspicions that similar effects may occur in humans. Included in these documented and suspected responses to PCBs are neurodevelopmental effects (A. Brouwer, M. Longnecker, L. Birnbaum, J. Cogliano, P. Kostyaiak, S. Schantz, and G. Winneke. 1999. Envir.. Health Perspect. 107:639-649;) and altered thyroid homeostasis (N,. Osius, W. Karmaus, H. Kruse, J. Witten. 1999. Envir. Health Perspect. 107:843-849; S. Poprterfield, 2000. Envir.. Health Perspect. 108:433-438). Of importance are reports indicating that pre-and postnatal exposures to PCBs may be of particular concern (A. Brouwer, M. Longnecker, L. Birnbaum, J. Cogliano, P. Kostyaiak, S. Schantz, and G. Winneke. 1999. Envir.. Health Perspect. 107:639-649).
Based on a limited review of the newer evidence, ADPH and ATSDR believe that it is reasonable to suspect that exposures to PCBs can induce a variety of responses in both animals and humans, and that some of those responses may occur as a result of exposures to environmental PCBs.
Commercial Areas, Area BN
Page 20, second paragraph of this section, first sentence: This sentence is somewhat awkward as written. It might be better to say, "Solutia has completed remediation activities at all the properties in Area BN to which it has been given access."
Response: The sentence has been clarified.
Area CP
Page 21, second paragraph of this section, first sentence: It is not correct that Solutia has " . . . removed all structures in the area. . ." Although Solutia did remove the structures on the eastern end of the area, a warehouse still stands on the western end of the property (the Miller property). It is correct to say, "By November 1999, Solutia had purchased the property and removed all but one of the structures,. . . "
Response: The sentence has been clarified.
Area XE
Page 24, first full paragraph: This paragraph is out of date. It would be better to replace "To-date" with "As of November 1999".
Response: The sentence was changed as noted.
Conclusions
Page 26, Conclusion 1 and Conclusion 2: Solutia disagrees that the concentrations of PCBs in the soils in the areas denoted in the conclusions could result in adverse noncancerous health effects for children. These conclusions are not supported by the scientific literature which discusses the human health effects of PCBs. The bases for Solutia's disagreement have been discussed in earlier comments. Solutia is confident that the levels of PCBs in the soils in the near-site areas to which children had or have access do NOT pose a public health hazard.
Response: This public health assessment was conducted by professionals trained in environmental health. Their weight of evidence evaluation of relevant data concludes that a public health hazard exists for designated populations. However, the word "noncancerous" has been removed from Conclusions 1 and 2.
Public Health Action Plan
Page 27, first paragraph of this section, line three and second paragraph of this section, line six: "Monsanto" should be replaced with "Solutia."
Response: The name has been changed to Monsanto Company/Solutia Inc. to remain consistent with the title of the public health assessment.
