Agent Orange Legacy
The NIEHS News (p. A116) updates efforts by U.S. and Vietnamese scientists to discuss research needs and priorities for a collaborative effort to study the environmental and human health effects of Agent Orange spraying during the Vietnam War.
Back to Basics in Environmental Health Nursing
Florence Nightingale, insisting on fresh air and clean water for her patients, was perhaps the first well-known environmental health nurse. After decades of emphasis on disease treatment--rather than disease prevention--environmental health considerations are once again becoming an integral part of the nursing profession, as described in this month's Focus (p. A118).
Unclogging the Carbon Sink Impasse
The use of forested lands for carbon sequestration is a source of bitter contention for advocates and opponents around the world. The Spheres of Influence (p. A124) examines the logistical and philosophical snarls surrounding the issue of carbon sinks.
Sniffing Out Pollutants
The Innovations (p. A128) takes a look at "smell-seeing" technology, which relies on vapor-sensitive dyes to change color when exposed to particular contaminants or toxins. This fast, inexpensive method puts researchers a nose ahead when it comes to rapidly discerning the presence of harmful substances.
Environmental Impacts of Health Care
In a Commentary, Kaiser et al. (p. 205) suggest that the health care industry use proactive decisions at all stages of the product life cycle. The authors recommend changes in purchasing, use, and disposal of health care products that should help prevent environmental pollution.
Sawmill Chemicals and Carcinogenesis
Huff (p. 209) reviews the carcinogenic potential of numerous sawmill chemicals and comments that virtually all chemicals associated with the wood industries are carcinogenic. He suggests that composite evaluations of carcinogenicity are required to properly evaluate the risks associated with occupational exposure to such multiple agents.
Exposure to Pyrethroids in Germany
Pyrethroid pesticides are prevalent in humans. They are metabolized and then eliminated in the urine. Heudorf and Angerer (p. 213) report background exposure to pyrethroids that appear to originate with the diet in 500 adults, 331 children under 6 years of age, and 247 children between 6 and 12 years of age. Further studies can use the reference values reported here.
Acrolein Inhalation and DNA Adducts
Penn et al. (p. 219) report that graded doses of acrolein, a prominent vapor-phase component of environmental tobacco smoke, elicited repairable DNA damage to artery walls. The authors suggest that frequent exposure to tobacco smoke may lead to persistent artery-wall DNA damage and provide sites where other plaque accelerant components of tobacco smoke can act.
Nickel and Platelet Activation
Molecular studies on the effect of nickel ions on platelet function were conducted by Riondino et al. (p. 225). The authors report that there are two phases in the process of platelet responses to nickel chloride stimulation, providing the first evidence of a direct role of nickel chloride in inducing receptor activation in platelets.
Rodent Reproductive Toxicity to DEHP
Moore et al. (p. 229) examined the toxicity of di(2-ethylhexyl) phthalate in male rats exposed in utero and during lactation. The pattern of developmental toxicity differed from that of other phthalate esters and appeared to be unique among all chemicals in that there was a preponderance of anterior prostate agenesis, suggesting that the mechanism of action of DEHP is distinct from that of other antiandrogens.
Estrogenicity of UV Screen Chemicals
Six frequently used UVA and UVB sunscreen additives were tested by Schlumpf et al. (p. 239) for estrogenicity using MCF-7 cell proliferation, pS2 protein induction, estrogen antagonist, and rat dermal and oral uterotrophic assays. All but one chemical tested positive in some assay, suggesting that all UV screens should be tested for estrogenic activity.
Effects of Arsenic on Glucocorticoid Receptors
Kaltreider et al. (p. 245) examined the effects of arsenite on the biochemical function of the glucocorticoid receptor-mediated regulatory pathway in hormone-responsive H4IIE rat hepatoma cells. Molecular assays suggested that the mechanism of activity appears to involve nuclear events rather than alterations in steroid-induced nuclear translocation and may represent a new class of endocrine disruptors for arsenic. (Also see Science Selections, p. A132)
Mycotoxins in South African Corn
The exposure of South Africans to mycotoxins was reported by Chelule et al. (p. 253). The levels of fumonisin B1 in maize were found to be lower than in other regions where there was an association of mycotoxin with esophageal cancer, suggesting that the risk of tumors was also lower. (Also see Science Selections, p. A132)
Transformation of Medaka Sexes by Estradiol
Melo and Ramsdell (p. 257) report that estradiol alters aromatase in medaka by inducing an anterior-posterior profile of enzyme activity in the hypothalamus, which resembles that of a female fish. Positive feedback regulation of estradiol is a mechanism that can lead to endocrine disruption in the presence of small alterations in estrogen
levels.
Impacts of PCB/Dioxin Exposure in Belgium
Animal feed containing PCBs and dioxins was distributed to farms in Belgium in 1999. Van Larebeke et al. (p. 265) report that PCBs contributed more to toxicity than the dioxins, and estimate that ingestion in foods could result in 40-8,000 cancers and/or neurotoxic and behavioral effects in neonates. (Also see Science Selections, p. A133)
PCBs Stimulate Uterine Contraction
In an in vitro test, Bae et al. (p. 275) exposed uterine strips from pregnant rats to Aroclors 1242, 1248, and 1254 and showed that increased uterine contractions resulted from Aroclors with decreased chlorination. Reductive dechlorination of the Aroclors by microbes from the Hudson River yielded ortho-substituted products that further enhanced uterotonic activity.
Lead in Calcium Supplements
Gulson et al. (p. 283) evaluated the contribution of lead from calcium supplements that were taken by adults at the recommended daily doses for 6 months. Significant changes in the isotopic composition of lead in blood occurred after calcium carbonate intake, suggesting that there was input of lead from diet into the blood. The authors recommend further studies, particularly in children, whose lead absorption is higher than in adults.
Chlorophyll Accelerates Dioxin Excretion
Morita et al. (p. 289) exposed rats to seven types of polychlorinated dibenzo-p-dioxin and 10 types of polychlorinated dibenzofuran and demonstrated that feeding chlorophyll resulted in a dose-related increase in contaminant excretion. The authors suggest that chlorophyll derived from Chlorella effectively prevents dioxin absorption from the diet.
Lead Genotoxicity in Battery Workers
In a study of occupational lead exposure in Bulgarians, Vaglenov et al. (p. 295) found a dose-related association between blood lead and the frequency of binucleated cells with micronuclei in peripheral blood lymphocytes. The authors concluded that blood lead is a good indicator of genetic damage and that lead concentrations higher than 1.20 µM/L may pose a genetic risk.
Organophosphate Pesticides in Children
Lu et al. (p. 299) analyzed six dialkylphosphate organophosphate pesticide metabolites in 110 children between 2 and 5 years of age. At least one metabolite occurred in 99% of the children, and two predominant organophosphate metabolites occurred in 70-75%. The authors concluded that some exposure was likely due to diet and that garden pesticide use was associated with elevated metabolite levels.
Lung Cancer in a Uranium Miner
Mulloy et al. (p. 305) report the case of lung cancer in a 72-year-old male who had worked in underground uranium mines, but had never smoked tobacco or had other significant occupational or environmental exposures. The authors report that radon decay products, silica, diesel exhaust, and other occupational exposures in underground uranium mines may be responsible for lung cancer in an increasing number of uranium miners.
Last Updated: March 19, 2001