4. Consideration of Health Risks and Guiding Principles for Making Recommendations

What is Low-to-Moderate? The Task Force relied on Ecology's current views about what constitutes "low-to-moderate" levels of arsenic and lead in soil. For schools, childcare centers, and residential land uses, in general, Ecology considers arsenic concentrations of up to 100 total mg/kg and lead concentrations of up to 500-700 total mg/kg to be within the low-to-moderate range. For properties where exposure of children is less likely or less frequent, such as commercial properties, parks, and camps, Ecology considers arsenic concentrations of up to 200 total mg/kg and lead concentrations of up to 700-1,000 total mg/kg to be within the low-to-moderate range.

As described earlier in this report, the Task Force charter specifically excluded evaluation of the MTCA soil cleanup standards for arsenic and lead, the risk policies underlying the cleanup standards, and the technical methods used to establish the standards. Nonetheless, to develop appropriate recommendations, the Task Force discussed the potential risks posed by arsenic and lead, reviewed some of the available information on potential health effects from exposure to low-to-moderate levels of arsenic and lead in soil, and heard presentations from experts. Information provided to the Task Force on the potential health effects of arsenic and lead is summarized in Appendix H. From this evaluation, the Task Force reached a number of conclusions:

• As described later in this report, concentrations of arsenic and lead in soil are above State soil cleanup levels in some areas of Washington State.
  
• The risk of developing health problems from arsenic or lead depends on the amount of exposure and the concentrations to which a person is exposed. The greater the exposure and/or the greater the concentrations, the greater the risk. Most information about the health effects of arsenic and lead comes from studies where exposures were greater than those expected from living and working in places with low-to-moderate levels of arsenic and lead in soil.
  
• Scientific studies to date have not found conclusive evidence that exposure to low-to-moderate levels of arsenic and lead contamination in soil has caused or is causing deleterious health effects in Washington residents. The number of pertinent studies is small, and their designs lack sufficient power to detect the presence of increased incidences of adverse health effects, if any do exist. Health monitoring and research studies have not been carried out to the extent necessary to understand and document whether exposure to low- to moderate-level soil contamination is causing or contributing to long-term health problems.
  
• Evaluating health effects at lower levels of exposure is difficult and expensive. It is unlikely that conclusive scientific information to determine the health risks, if any, from exposure to area-wide soil contamination will be available in the foreseeable future. In light of this uncertainty, there is disagreement among scientists about how the information that is available should be interpreted and used to assess the risks of exposure to low- to moderate-level soil contamination. Some members of the scientific community argue that Federal and State efforts to address low- to moderate-level soil contamination are not scientifically justified because there is no information demonstrating that health problems are being caused by exposure to such contamination. Other members of the scientific community argue that arsenic and lead in soil have the potential to cause health problems at low levels of exposure-especially for people, such as young children, who are particularly sensitive to the effects of these contaminants. Task Force members mirrored this diversity of views. In recent years, the majority of scientific review committees formed to evaluate the available scientific information on arsenic and lead have concluded that there is a sufficient scientific basis to justify efforts to reduce exposure to all sources of arsenic and lead, including arsenic and lead occurring in soil.
  
• Arsenic and lead are both considered persistent contaminants. This means that they bind strongly to soil and usually remain in the environment without breaking down or losing their toxicity, and thus can be a source of exposure for many decades.

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In light of these conclusions, the Task Force developed six guiding principles. These principles guided the Task Force's deliberations and recommendations and should guide the Agencies and other organizations' implementation of Task Force recommendations:

• A balanced approach is needed: The Task Force believes that responses to area-wide soil contamination should be effective, practical and affordable.
  

• 	What Home Remedies Contain Lead? Some home remedies or medicines contain lead and can make people, particularly young children, very sick, even though symptoms of lead poisoning might not be immediately evident. Home remedies containing lead include: > Azarcon and Greta are bright powders used in the Hispanic community to treat intestinal illness or "empacho." They are almost 100% lead. > Pay-loo-ah is a red powder used in the Hmong community to treat rash or fever. Ghasard, Bala Goli, and Kandu are Asian Indian remedies for stomachaches. > Kohl and Surma are used in Arab communities for cosmetic and medicinal purposes.

  Lower adverse health risk: Despite the fact that concentrations of arsenic and lead in soil may be above State soil cleanup levels, the Task Force believes that the level of risk associated with exposures to low-to-moderate arsenic and lead soil contamination appears to be relatively low when compared to risks at sites where smelters operated or where lead arsenate pesticides were mixed (i.e., sites with higher concentrations of contaminants). Resources to address contaminated sites in Washington State are limited, and addressing area-wide soil contamination sites will compete for resources with addressing more traditional cleanup sites. Beyond the broad-based education and awareness-building described below, the Task Force does not recommend that additional remediation responses are needed at every individual property with low-to-moderate arsenic and lead soil contamination, unless exposure potential exists for children or the likelihood for enhanced exposure potential exists for adults through activities such as gardening.
  
• Focus on controlling exposure: Given the potential for exposure to arsenic and lead to cause adverse health effects in people, it is prudent to take effective, practical, and affordable steps to minimize the potential for exposure to arsenic and lead in soil.
  

• 	Lead-Based Paint Nationwide, the most common source of lead poisoning in children is lead-based paint. Lead was used extensively in interior and exterior paint before 1950 and may be present in any home built before 1978. Lead-based paint is most dangerous when it is peeling, chipping, chalking, or cracking. Children can be exposed to lead by eating paint chips, chewing painted surfaces, or ingesting soil or dust contaminated from lead-based paint.

  Focus on children: While adults are also vulnerable to adverse health effects from arsenic and lead and should not be ignored, the Task Force felt a special responsibility to address protection of children. Resources devoted to assessing and responding to area-wide soil contamination should be focused on locations where there is the highest risk of exposure and should be targeted at protecting children. The vulnerability of the population, likelihood of exposure, and the duration or frequency of exposures are the most important factors in deciding whether response actions are necessary and, where actions are needed, in selecting the specific actions selected.
  
• Responses increase as exposure increases: Responses to area-wide soil contamination should be commensurate with the level of risk associated with potential exposure. In general, the intensity and effectiveness of responses to area-wide soil contamination should increase as exposures become more likely (because of likelihood of extent of contact), more prevalent (because of more individuals exposed), or more intense (because of longer duration or more frequent exposures). In some situations, higher concentrations of arsenic or lead may be found in areas affected by area-wide soil contamination; in these cases, more aggressive response actions may be warranted.
  
• Decisions should be made locally: The Task Force recommends what it believes are effective, practical, and low-cost methods to respond to area-wide soil contamination. However, the Task Force recommendations are only guidelines. Each person or community affected by area-wide soil contamination should implement a response that meets their priorities, objectives, and tolerance for risk, even if those responses differ from those recommended by the Task Force. For example, some individuals or communities might choose not to implement Task Force recommendations. Other individuals or communities might choose to remove contaminated soil because they do not want the added complication of maintaining protection measures over time, even though less costly actions focused on individual protection measures and maintaining soil cover would also be effective.

Using these guiding principles, the Task Force considered a wide range of protection measures and developed the recommendations in the remainder of this report.

One Task Force member expressed strong and persistent concerns about the wisdom of the Task Force process, believing that it was inappropriate to exclude consideration of the MTCA cleanup standards from the Task Force charter and that the process failed to demonstrate any link between human health risk to lead and arsenic in the soil. This Task Force member asserts that a full evaluation of these issues would show that the MTCA cleanup levels for arsenic and lead in soil are set too low given current and historical human health-related data regarding this complex issue and should be revised. Although this Task Force member supports efforts to reduce potential exposure through education and awareness building efforts, he chose not to sign the final report because of concerns over recommendations dealing with funding future mapping projects and the potential economic impact of creating area-wide soil contamination zones. He remains very concerned about possible overreaction to area-wide soil contamination that could lead to unwarranted fears by the public and media, potential damage to local and state economies, and overregulation by government in response to this issue.

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