IMPACTS ON HUMAN HEALTH 3.16 IMPACTS ON HUMAN HEALTH This discussion of impacts of proposed herbicide use on human health comes mainly from the environmental statement on Vegetation Management with Herbicides--Western Oregon (USDI, BLM 1978d) describing herbicide use for Oregon. The possibility of human health being impacted by the proposed use of herbicides on 29,690 acres is related to the likelihood of exposure and the toxicity of the chemicals proposed for use (Norris 1978). Exposure of humans to herbicides could be direct, as in the case of applicators or outdoor enthusiasts, or indirect. The number of persons that could be directly affected is very small. Exposure from contact with contaminated streams is more likely to occur than is direct exposure. The two most likely sources of stream contamination are direct application to to surface waters and drift from nearby spray areas. Project design features (Section 1.5.4.2) would minimize both of these contamination sources and reduce risk of exposure. Particular care would be taken to avoid exposure of the six residences within 1 mile of spray areas proposed in the 1-year herbicide plan (Appendix B). The chance that humans exposed to herbicides used in timber management would be adversely impacted is also related to the toxicity of the herbicides. Research has shown that the chemicals proposed for use are relatively nontoxic to humans. Therefore, it is expected that exposure under most circumstances would not result in injury to human beings. Selected information on the relative toxicity of herbicides and other chemicals in everyday use was compiled by Heikes (1967). This information is displayed in Table 3-16. Because neither 2,4,5-T nor silvex would be used, there would be no TCDD introduced into the environment. Because the likelihood of exposure, both direct and indirect, is small and the chemicals proposed are nontoxic or slightly toxic, the impacts of herbicide use on human health are minimal. 3.17 IMPACTS ON ENERGY USE Due to the types of equipment employed and the level of treatments included, the proposed action would be considered energy intensive. Table 3-17 indicates the energy investment required, as expressed in British thermal units (Btu's). Energy required for processing of logs into lumber, plywood, etc., is not included since manufacturing costs vary vary widely depending on mill efficiency. The secondary energy investment for milling is 62,000 Btu's per dollar of manufacturing cost. The annual energy consumption attributable to the proposed action would be 1.493 trillion Btu's. Of this, 1.408 trillion Btu's, or 94 percent of the total, is attributable to road development and care (construction, reconstruction, surfacing and maintenance) and log production. Such operations involve *Included for a comparison with chemicals in everyday use. 1/ LD 50 is the rate at which test animals were fed in relation to body weight (mg/kg) and half or 50 percent of the test animals died (Lethal dose, 50 percent). Source: USDI, BLM. Vegetation Management with Herbicides - Western 1 ounce 1 pint 15,000 & above NOTE: BLM estimated costs per units were often a range of values. The listed costs were selected as indicative of the JKS YUs situation. Similarly, DOE energy requirements were also given as a range in Sources: some cases. BLM data except for Assumed Energy Requirements per Dollar of heavy equipment and machinery, the energy efficiency of which is dictated by available technology. About 6 percent of the total consumption, approximately 90 billion Btu's, is due to other management practices of the proposal. The actions involved are for the purpose of optimizing the sustainable timber production level. 3-17 were all expended in If the 1.493 trillion Btu's identified in Table 3-17 were the form of gasoline, it would equate to 11.9 million gallons which amounts to 0.9 percent of the 1.362 billion gallons of gasoline consumed in Oregon during 1977. |