A Commentary by Weinstein argues that effective control of a vector-based disease like the mosquito-born Ross River virus in Australia should be based on a thorough understanding of the ecology of the disease, especially when changes that occur are brought about by global warming, increased rainfall, or altered demographics.
An NIEHS-sponsored environmental justice grant program funds projects around the country for medically underserved communities. The
NIEHS News describes innovative strategies being used to teach members of such communities how to work with local organizations, scientists, and health care providers to address their environmental disadvantages.
The EPA is gearing up to issue controversial new air quality standards for ozone and particulate matter, which are presented in the
Focus article. Some scientists question the new standards' scientific soundness and whether they are an effective means of reaching the EPA's goals. Meanwhile, industries and cities brace for the impact of implementation of the standards, which will catapult many areas of the country into nonattainment status.
Conservatives and conservationists compare notes on the environmental consequences of the 104th Congress in the
Spheres of Influence. Members of each group have published a "scorecard" that examines key environmental issues from the 1995 and 1996 sessions and "grades" both the laws and the lawmakers. Insiders predict the battles to come in the 105th Congress.
Plastics make up approximately 20% by volume of the waste stream and constituted an estimated 19.8 million tons of municipal solid waste in 1994. The
Innovations outlines a cheaper, more energy efficient method for recycling plastics developed by researchers at Rensselaer Polytechnic Institute
Lasky and Magdar
Review the molecular epidemiology of
p53 mutations to examine possible correlations between particular mutations (such as G>T transversion at the third base pair of codon and specific environmental carcinogens like aflatoxin to assess the quality of the data for this relationship. The authors conclude that data are insufficient to conclude that
p53 mutations serve as reliable markers for aflatoxin exposure.
A
Review of lead exposure in 16 Latin American and 2 Carribbean countries by Romieu et al. indicates that leaded gasoline is a major source of contamination, sometimes containing more than 2 g lead per gallon. Exhaust pollution is a particular problem in urban areas where 75% of the population with 30% of the children live. Additonal lead sources identified include industrial emissions, radiator shops and car batteries, paint, and lead-contaminated food and water. While three quarters of the countries recognize the problem and half have some legislation to control lead pollution, continued efforts to reduce lead toxicity in these regions are needed.
Lead exposure in children living in proximity to a lead smelter in the Czech Republic was measured by blood and tooth lead analyses by Cikrt et al. . Average blood lead was 11.35 µg/dl and the geometric mean for tooth lead was 6.44 µg/g, lower than that reported in 1986-1990; differences were attributed to analytical methods rather than to exposure conditions. Risk factors for children's exposure to lead were based on airborn lead and soil lead contamination in proximity to the smelter. Soil lead content was not the single determinant for bioavailability of lead because of many confounding factors including species, size, and age of lead particles.
A rodent animal model was used by Han et al. to examine lead retention in bone from childhood into adulthood. Weanling rats were given lead in drinking water for 5 weeks beginning at ages 5, 10, or 15 weeks; and after 4 weeks withdrawal, blood and organ lead were determined. Additional rats were exposed at 5 weeks of age and examined 8 and 20 weeks after cessation of treatment. Bone lead declined with time, but rats exposed at the youngest age exhibited higher bone lead 20 weeks after termination than did older rats only 4 weeks after cessation of lead ingestion. The data suggested that lead exposure at a younger age is associated with greater lead retention and toxicity, even in the absence of continued exposure.
Arukwe et al. examined induction of proteins in Atlantic salmon and report that vitellogenin and zona radiata proteins (zrp) are induced by exposure to two xenoestrogens, 4-nonylphenol or effluent from an oil reinery treatment plant. The zrp-ß was more reponsive than the zrp-
and zrp-
and also more than vitellogenin, suggesting that it was a more ecologically significant biomarker of estrogenicity.
Mercury in urine and blood was examined in tribal members living next to an inactive mercury mine in California. Harnly et al. report that urinary mercury was no different than background levels, indicating that soil and dust exposure was inconsequential. Average blood organic mercury was 15.5 µg/l compared to 2 µg/l in non-fish consumers with a significant correlation between fish consumption and blood organic mercury. Twenty percent of the population may be at risk from mercury toxicity, indicating a need for public health intervention, especially for commercial fish consumers.
Children with mild asthma from Sokolov were examined for respiratory function and were asked to keep a diary with symptoms and medication use. Peters et al. report that sulfate particles in the air with diameters less than 2.5 µm were associated with respiratory symptoms in 51 non-medicated asthmatics. There was an increase in the use of beta-agonist medication in 31 asthmatics in association with an increase in sulfate air pollution; however the medication did not ameliorate decreased respiratory function or the prevalence of cough.
