Document YDL6k4QZ9nqNm19jVep4dyVrD

PLAINTIFF'S EXHIBIT V,A A/C Pipe Producers Association Internal Correspondence / / A to Board of Directors j^iteyrrnmattikoinEaldAiffairs Committee DAV>'- June 14, -198"4 *G fz' pR^yj. F. Welch, Vice-President \c-> v/ r.c O-1 World Heaith Organization fWHO) - Guidelines for Drinking Wab'^hality^- '' SUBJECT ACTION REQUIRED: Review for information Enclosed are excerpts from the recently published WHO Guidelines for Drinking Water Quality. As with the previous Guidelines, WHO did not establish standards for asbestos in drinking water, noting "... available data are, at present, insufficient to determine whether a guideline value is needed." This position is very conservative and probably reflects WHO's incomplete knowledge of the medical and scientific evidence supporting the absence of health risks from ingested asbestos. According to other documents provided by the Asbestos International Association, WHO also is preparing a background document on asbestos in drinking water. The document explains why WHO did not establish an asbestos guideline. The background document does not contain the proceedings of EPA's Summary Workshop on Ingested Asbestos, the Ontario Royal Commission Report and other studies. No references later than 1979 are included so it is understandably tentative and guarded. A copy will be distributed when it is finalized. Staff Recommendation The absence of WHO guidelines for asbestos in drinking water should be used by AACPP member companies to support the safety of A/C pipe. If WHO had any evidence or reasons to believe that A/C pipe might hazardous to human health, it goes without saying that they would recommend guidelines. If you have any questions, please do not hesitate to call. JFW/bwm cc:A. H. Kahn, Esq. copies to: Board of Directors International Affairs Committee L. Ambler F. Layton L. Taylor--'^ L. Cejudo J. M. Couture E. van der Rest A. Junes G. Zaviezo C. Barton H. Hudson P. Hart V. Pattabhi S. Al-Tarkait C. Saeng-Xuto J. Glanville M. Delcourt L. Doulbeau D. Dorner E. Costa J. Schmaus F. Mansour R. Hobbs A. Saoulis R. Jalan B. Dubois R. Cairns M. Elola B. Giboin A. Lluch 0172061307 Chrono CAPCO JEN 0032352 i GUIDELINES FOR DRINKING-WATER QUALITY Volume 1 Recommendations World Health Organization Geneva 1984 i CAPCO JEN 0032353 4. CHEMICAL AND PHYSICAL ASPECTS 51 this document are based upon the selection of an acceptable risk of less than 1 additional case of cancer per 100000 population assuming a daily consumption of 2 litres of drinking-water by a 70-kg man. The cancer risk associated with other concentrations of these substances can be readily calculated. 4.1.3.4 Apportionment of intake Drinking-water is not the only source from which man is exposed to many of the chemical constituents for which guideline values have been set. In many cases the intake from drinking-water may be small in relation to the intake from food and air. It was accepted that, in the evaluation of the health effects of inorganic constituents, all routes of exposure (air. food, and water) had to be considered when deciding upon a value for drinking-water. This, in some cases, proved to be problematical because of the lack of information concerning the biological availability of the contaminants present in foodstuffs. However, in the case of chemicals for which carcinogenicity is the main concern and for which the guidelines have been based upon lowdose extrapolation techniques in order to equate the recommended value with an incremental cancer risk, other sources of exposure have not been considered. The incremental risk from food, air, occupation, etc., will be additional to that from drinking-water. As regards pesticides, a special situation exists. In this case, the ADI has already been "used up" in setting tolerances for pesticide residues in foods. On the other hand, measurable quantities (although usually at very low concentrations) are frequently found in drinking-water. Therefore in setting guideline values for pesticides in drinking-water, values were generally based on committing not more than I % of the ADI. This was considered acceptable on the grounds that not atl food will contain pesticides at the permitted tolerance levels. 4.2 Health-related inorganic constituents. A series of working papers dealing with the health effects of 37 in organic constituents occurring in drinking-water were studied in order to decide upon guideline values for the undesirable inorganic substances in drinking-water (Table 7). 4.2.1 Guideline values recommended On the basis of the health-related data concerning the 37 inorganic constituents examined it was decided that, at the present time, guideline' values could be recommended for only 9 of them (Table 8). and the evidence is summarized in section 4.2.2. However, since the effects on health of several other constituents in the list are the subject of current debate, brief explanations of the > I / CAPCO JEN 0032354 52 / GUIDELINES FOR DRJNKING.WATEBKQUALJTY zzTable 7. Inorganic constituents of potential health significance R*ten#d (or CCrtt*drtion of esthetic end Guid**mt document orginottcxic No *ciion \ ConmtuwH vaJtm Mt drah*d nceo requited i Juminium X r ntimony 1 *r**mc,^ XX t \ MOextOt' Xl btnum ' X ii beryllium X i boron ' CJKJrmum # X X : chromium XX X X cobett coppe X X Cynid frTOCVaAd# XX X fluonoe XX hvdnra \ (urioum *nd m*gnuum) XX l XX X l lithium X I nv*gniom mngn* X X mercury XX mohrbd^num X mcfcW X nitmt XX IWtf X /mum XX X ockum (Humeri thulium tfuocy>nM XX X X X tm X bumum tuogflen X X uremum vyoKkum nc X X X reasons why guideline values could not be recommended are also provided in section 4.2.2 for 7 other constituents. Eight of the constituents listed in Table 7, although not of direct health concern, could have an indirect effect upon health because of their effect on the aesthetic quality of drinking-water. These substances are dealt with later under "Aesthetic and organoleptic aspects" (page 77). ii CAPCO JEN 0032355 4. CHEMICAL AND PHYSICAL ASPECTS 53 Table 8. Guideline values (or health-related inorganic constituents Consciluvnt cxjrruum chromium evanida lluonoa mercury nitrate U* N> aetentum a Cw'dw w yiM GutffeUrt# vatu* (mgfbtre) oos 0.005 0.05 01 1.5* 005 0001 1000 001 *Kv dpwig upon chmatic cond*uons end ww centwmptie* 4.2.2 Summaries of the evidence used in setting guideline values 4.2.2.1 Arsenic Based on human health data, a concentration of 50 fig of arsenic per litre is not associated with any adverse health effects. Estimates have been made of the risk of cancer from low intakes of arsenic, but these are very uncertain. At an arsenic concentration of 50 fi g/litrc, the contribution made by water to the total intake will normally be about one-half to two-thirds; for very low dietary intakes of arsenic, the proportion provided by water may be somewhat higher. Arsenic in drinking-water will normally be the main source of inorganic arsenic. An arsenic concentration of 0.05 mg,litre is recommended as a guideline value. 4.2.2.2 Asbestos The health hazards associated with occupational exposure to airborne asbestos have been well documented. Epidemiological studies suggest that prolonged inhalation of asbestos also leads to an increased incidence of cancer of the gastrointestinal tract: however, it is not known whether such an effect is systemic or results from swallowing inhated fibres. The harmful effects of swallowed asbestos on human health h^ve not been determined. Studies in progress should permit a more complete evaluation of any hazard resulting from the swallowing of asbestos, but available data are. at present, insufficient to determine whether a guideline value is needed. 4.2.2.3 Barium There is no firm evidence of any health effects associated with the normally low levels of barium in water. Even at a barium concentration V \ CAPCO JEN 0032356