ICCVAM Completes Reviews
This month's NIEHS News (p. A118) describes two success stories of the Interagency Coordinating Committee on the Validation of Alternative Methods, which coordinates the development, validation, acceptance, and harmonization of new and revised toxicological test methods. The recently validated murine local lymph node assay and Corrositex assay both offer improvements in assessing dermal effects of chemicals while reducing the need for animal testing.
Gasping for Air in the Ocean
The causes and effects of hypoxic "dead zones" in coastal areas around the world are examined in the Focus (p. A120). Believed to be the result largely of agricultural runoff, such dead zones harm marine ecosystems, threaten fisheries worldwide, and, through encouraging algal blooms, may indirectly lead to adverse human health effects.
A New Crop of Biothreats
The same technologies that allow scientists to improve agricultural products and yields through plant disease prevention can also be used to build better biological warfare agents, turning bacteria, viruses, and toxins into potential weapons of mass destruction that attack crops, leaving behind famine and disease. The Spheres of Influence (p. A126) looks at both the realities and the possibilities of anticrop bioterrorism.
Earth-Sky Collaboration
Fertilizers and pesticides are a double-edged sword for farmers, capable of producing not only plentiful crops but also environmental hazards. The Innovations (p. A130) examines precision agriculture, which uses remote sensing technologies to help farmers enrich their fields more safely and effectively.
Jet Fuel Exhaust Exposure at U.S. Air Bases
Personal whole air samplers were used by Pleil et al.
(p. 183) to monitor Air Force personnel occupationally exposed to jet fuel. The authors found demonstrable exposure to JP-8 jet fuel for all subjects, ranging from slight to over 100 times the exposure of control subjects, indicating the need for further studies to recommend changes in personal protective equipment and to optimize reduction of risk of adverse health effects. (Also see Science Selections, p. A134)
Congenital Anomalies in South Americans
A study of the association between industrial activity and the occurrence of 34 different congenital anomalies was conducted in Argentina by Castilla et al. (p. 193). Increases in the prevalence of birth defects indicated that there were possible relationships between three different congenital anomalies and several local industries.
Genetics and Lead in Organolead Workers
A molecular genetic study by Schwartz et al. (p. 199) evaluated bone lead and polymorphisms in vitamin D receptors of former organolead manufacturing workers. The authors report that genetic differences in vitamin D receptors modified the relationships between age or years since last lead exposure and tibial lead concentrations. The authors suggest that variations in each person's genetic makeup could influence the lead or calcium content in their bones.
Inuits, Organochlorines, and Immunity
The relationship between blood DDE in 3-, 7-, and 12-month-old infants and ear infections was reported by Dewailly et al. (p. 205). Breast-feeding for prolonged periods exposed children to increasing DDE levels and resulted in demonstrable immunodeficiencies in the older children, suggesting that cumulative organochlorine exposure may be a risk factor for ear infections in Inuit children.
Air Pollution in Harlem
Kinney et al. (p. 213) used personal exposure measurements to evaluate exposure to diesel exhaust and particle pollution in urban core neighborhoods. Variations occurred in air pollution in direct relation to diesel traffic density and in locations where the greatest number of people were exposed to diesel exhaust particles. The study exemplified the value of cooperation between scientists and community-based organizations when investigating environmental problems.
Sex Reversal in Fish Injected with DDT
Edmunds et al. (p. 219) report complete, permanent, and functional male-to-female sex reversal in Japanese medaka after a single injection of an embryonic dose of o,p´-DDT (227 ng/egg). The authors state that the results indicate that this weakly estrogenic pesticide alters sexual differentiation if presented during a critical period of gonadal development and, by extension, could also significantly affect the dynamics of other fish populations.
The NC Livestock Industry: Environmental Injustice and Environmental Health
Wing et al. (p. 225) and Wing and Wolf (p. 233) report that corporate hog operations in North Carolina are concentrated in nonwhite, high-poverty neighborhoods. The confined animal feeding operations use waste pits that can contaminate groundwater and are located in the coastal plain region where wells are the predominate water source. These locations threaten environmental justice by reducing land values, lowering the quality of life, and impeding healthier economic development. Respiratory and gastrointestinal problems were greater in the residents of the region of corporate hog operations than in those living near intensive cattle operations; the quality of life, although similar in control and cattle communities, was adversely affected by odors associated with the corporate hog industry, as judged by the unwillingness of residents to open windows or to go outside. (Also see Science Selections p. A134)
Variability in Bone Lead Measurements
K X-ray fluorescence is used as a noninvasive technique to estimate long-term lead exposure in adults. Hoppin et al. (p. 239) used leg bones (tibiae) from 17- and 20-year-old cadavers to determine the extent of the variability in bone lead measurements in young adults. Lead was measured from each tibia at different locations; measurement uncertainty increased at locations 1 cm from the center of the tibia and between each leg. These data will help interpret bone lead concentrations in live subjects subjected to chronic lead exposure.
Bisphenol A Toxicity in Two Rodent Strains
Bisphenol A is a monomer reported to leach from food packaging and epoxy-based dental applications. Rodent animal models differ in responsivity to the xenobiotic. Long et al. (p. 243) found that two rat strains exhibit differences in cell sensitivity to bisphenol A, suggesting that caution is warranted when selecting toxic end points and animal models for tests of the estrogenic effects of xenobiotics.
Endocrine Disruption Studies in Fish
Sexual development in trout and salmon embryos after treatment with high doses of o,p´-DDE was adversely effected, but lower doses of DDE, various isomers, and octylphenol were ineffective in altering sexual development, steroid production, or spawning success. Carlson et al. (p. 249) suggest that average environmental levels of the chemicals tested are unlikely to affect endocrine development in salmonid fish.
Reanalysis of Methylmercury Toxicity
Crump et al. (p. 257) used a benchmark dose analysis of the Seychelles methylmercury data set (where offspring were exposed by consumption of fish by pregnant mothers) similar to that used by the U.S. Environmental Protection Agency when they developed a reference dose for methylmercury using the Iraqi data set (where offspring were exposed by pregnant mothers consuming methylmercury-contaminated grain). The authors suggest that these types of analyses are scientifically sound and should be considered when developing an exposure advisory for methylmercury.
Children Exposed Chronically to Ozone
For 1 year Geyh et al. (p. 265) monitored exposure to ozone in California elementary school children. Homes of participants were monitored for indoor and outdoor ozone on a daily basis, children were monitored with small passive ozone samplers, and daily activities were recorded in diaries. During the summer ozone season, measured concentrations were higher in mountain towns than in the lower-elevation town of Upland, and personal exposure was found to differ by community and sex, but not by age group.
Last Updated: March 3, 2000
