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Obesity and asthma have reached epidemic proportions in the United States. The reasons for these epidemics are complex, and the solutions to address them are many. This article explores the epidemics, their causes and consequences, associations and relationships, an expansion of the definition of the environment, and current national initiatives that address the components of the built and social environments that promote obesity and precipitate asthma.

This paper analyzes the role of threshold limit values (TLVs) in national air pollution policy during the 1980s, a period in which the Environmental Protection Agency (EPA) sought to delegate to individual states the authority to evaluate and regulate airborne toxic substances. We focus on 20 carcinogens and 11 substances with non-genotoxic health effects that were regulated by local air toxics programs using TLVs. Data from EPA's National Air Toxics Information Clearinghouse indicate that maximum TLV-based Ambient Air Level guidelines (AALs) frequently exceed minimum TLV-based AALs by a factor of greater than 1,000. Cancer potency data from EPA's Integrated Risk Information System suggest significant risks remain at TLV-based AALs. Cancer risks at the median TLV-based AAL exceed 1,000 cases per million exposed persons for cadmium (1,040), nickel and its compounds (1,420), propylene oxide (1,550), coke oven emissions (1,860), benzene (2,500), arsenic and its compounds (7,300), N-nitrosodimethylamine (21,000), asbestos (21,500), and ethylene dibromide (55,000). We also summarize published studies that report non-genotoxic health effects in workers exposed at levels near the TLV for 11 substances whose AALs were based on TLVs. Contrary to the assumption frequently made by state air toxics program, TLVs cannot be taken to represent no observed effect levels (NOELs) for regulatory purposes.

lu c ea OSHA's Four Inconsistent Carcinogen Policies Background No issue has proven more conten- tious in occupational health policy than the control of chemical carcinogens. The Occupational Safety and Health Admin- istration (OSHA) has focused much of its efforts on cancer risks, both through sub- stance-specific regulations and through broader efforts to establish generic poli- cies and work practices. The 1980 Generic Carcinogen Policy was conceptualized as the centerpiece of OSHA's shift from sub- stance-specific to generic regulations cov- ering hundreds if not thousands of sub- stances. Despite adverse judicial rulings and a generally anti-regulatory political climate, OSHA continued to pursue a ge- neric approach to occupational health hazards during the 1980s, particularly through its 1983 Hazard Communication Standard and 1989 Air Contaminants Standard. The legal and political wran- gling have left deep scars on OSHA's strategy, however. While consistency and comprehensiveness were once the princi- ples underlying OSHA's efforts to control carcinogens, the current collection of pol- icies and regulations is remarkable for the inconsistent and incomplete way in which suspect chemicals are treated. In this paper, we analyze OSHA's four carcinogen strategies, as embodied in the Generic Carcinogen Policy, the sub- stance-specific carcinogen regulations, the Hazard Communication Standard, and the Air Contaminants Standard. Two issues are of particular interest. Given the inherent methodological limitations to epidemiological data on oc- cupational and environmental cancer, a June 1991, Vol. 81, No. 6 an e avv major scientific and policy debate has de- veloped over the appropriate use in hu- man risk assessment of laboratory evi- dence on chemical carcinogenesis in animals. The four OSHA policies exhibit quite different positions on this debate. 0 The choice between direct regula- tion and indirect labor market pressure, and the stringency of those exposure lim- its that are imposed, reflect different atti- tudes toward the appropriate balance of economic costs and health benefits for oc- cupational health regulations. OSHA's four policies reflect dramatically different balancing efforts. We begin with the Generic Carcino- gen Policy, which remains OSHA's for- mal policy on the issue but which has been blocked by administrative stays and never incorporated into risk management pro- grams. The substance-specific cancer standards are then analyzed in terms of their comprehensive treatment of a few public health hazards and neglect of many others. While partially an attempt to pre- empt stronger state and local regulations, the Hazard Communication Standard is in many ways both comprehensive and in- novative, covering a wide range of chem- icals and imposing duties on employers that could potentially lead to substitution of alternative products and processes. Given its current prominence as the cen- terpiece of OSHA's regulatory program, the Air Contaminants Standard receives the greatest emphasis. Containing its own internal inconsistencies, the Air Contam- inants Standard embodies the best and the worst of OSHA's new regulatory philos- ophy and its strategy for controlling chem- ical carcinogens in the workplace. T7e GenericCarcinogen Poly OSHA's Generic Carcinogen Policy1 was a response to two complementary concerns that emerged over the course of the 1970s and came to dominate the agen- cy's agenda. OSHA had devoted a sub- stantial portion of its resources to the reg- ulation of individual carcinogens but had achieved only meagre results. The agency leadership faced growing demand for an accelerated regulatory timetable from Congress, organized labor, and environ- mental groups. Of equal significance, per- haps, was the competition among several federal agencies for leadership in formu- lating governmental policies with respect to chemical carcinogens. Proposed in 1977 and promulgated in 1980, OSHA's Ge- neric Carcinogen Policy embodied a highly protective approach to chemical carcinogenesis. Based on the most con- servative set of assumptions concerning methods of cancer induction and the most stringent set of requirements for exposure controls, the 1980 policy represents the high water mark of governmental enthu- siasm for regulating occupational and en- vironmental carcinogens. OSHA devoted much of its energies during the 1970s to developing standards regulating exposure to occupational car- cinogens, including asbestos2 in 1972, vi- nyl chloride3 and a group of 14 chemicals4 in 1974, coke oven emissions5 in 1976, plus benzene,6 dibromochloropropane (DBCP),7 inorganic arsenic,8 and acry- From the Center for Occupational and Envi- ronmental Health, University of California, Berkeley. Address reprint requests to James C. Robinson, PhD, Center for Occupational and Environmental Health, School of Public Health, University of California, Berkeley, CA 94720. This paper, submitted to the Journal June 20, 1990, was revised and accepted for publication January 30, 1991. George J. Annas, JD, MPH, Chair, Health Law Department, Boston University, Schools of Public Health and Medicine, 80 East Concord Street, Boston, MA 02118, is editor of the Public Health and the Law column. American Journal of Public Health 775

This paper evaluates the decision by the Occupational Safety and Health Administration (OSHA) to base its Air Contaminants Standard on the threshold limit values (TLVs) of the American Conference of Governmental Industrial Hygienists. Contrary to the claim made by OSHA in promulgating the standard, the TLV list was not the sole available basis for a generic standard covering toxic air contaminants. The National Institute for Occupational Safety and Health (NIOSH) presented data indicating that the TLVs were insufficiently protective for 98 substances. NIOSH Recommended Exposure Limits (RELs) were available for 59 of these substances. The ratio of PEL to REL ranged up to 1,000, with a median of 2.5 and a mean of 71.4. OSHA excluded 42 substances from the standard altogether despite the availability of NIOSH RELs, solely because no TLV had been established.

We compare the information used by the Occupational Safety and Health Administration (OSHA) to regulate carcinogens under its 1989 Air Contaminants Standard to publicly available information on substances with potential carcinogenic activity. Carcinogenicity evaluations were obtained from the National Institute for Occupational Safety and Health (NIOSH), the American Conference of Governmental Industrial Hygienists (ACGIH), the National Toxicology Program (NTP), the Environmental Protection Agency (EPA), and the International Agency for Research on Cancer (IARC). We focus on three sets of substances: those which were regulated as carcinogens by OSHA in the Standard, those which were included in the Standard but whose exposure limits are based on noncarcinogenic effects, and those substances designated as potential carcinogens by NIOSH, ACGIH, and/or NTP but which were excluded from the Standard. The data indicate that OSHA relied almost exclusively upon the recommendations of the nongovernmental ACGIH to the exclusion of IARC and the three governmental bodies. Given their statutory authority to evaluate chemical carcinogenicity for regulatory agencies such as OSHA, the exclusion of NIOSH and NTP is particularly striking.