Health Is No Mirage in Southwest Desert
This month's NIEHS News (p. A206) spotlights the Community Outreach and Education Program of the Southwest Environmental Health Sciences Center in Tucson, Arizona. The program educates the public about the environmental health issues specific to American Indians and the Southwest, with particular attention to children in grades K-12.
Everything Old Is New Again
Indigenous or traditional knowledge may provide science with a font of empirical information on plants, animals, and ecosystem management. Some fear, however, that incorporating such information into research will water down the scientific method and endanger human health. The Focus (p. A208) discusses efforts to take advantage of indigenous knowledge while maintaining safety and scientific credibility.
DNA: A Matter of Principle
Genetic variation and disease susceptibility among indigenous groups can provide important clues to the genetic and environmental components of disease. But many indigenous groups are wary of genomic researchers and scientific intrusion into their privacy and culture. The Spheres of Influence (p. A216) describes the current impasse between American Indians and genomic researchers and efforts to improve relations between the two groups.
Environmental Ferry Godmother?
The Innovations (p. A220) tells how a team of North Carolina scientists has put together a project using that state's extensive coastal ferry system to constantly monitor river and sound water quality. Data on baseline water quality and information on nutrient runoff, storm impacts, and other factors will give insight into how to ameliorate the environmental and health effects of ecological change along the coast.
Peroxisomes and DEHP
Di(2-ethylhexyl)phthalate (DEHP) is listed as a possible human carcinogen based on rodent cancer tests that rely on peroxisome proliferation as a mechanism of action. The commentary by Melnick (p. 437) emphasizes that humans remain at risk for cancer from DEHP even though they are unresponsive to peroxisome proliferation and that peroxisome proliferation is unproven as an obligate pathway for the carcinogenicity of DEHP.
Plant Defenses against Herbivory
In a review of the evolutionary significance of plant defenses against herbivory, Wynne-Edwards (p. 443) develops hypotheses that argue for novel solutions for dealing with endocrine disruptor susceptibility in vertebrates. The author recommends that comparative endocrine physiology be used in developing models for screening endocrine disruption in diverse vertebrate species.
Gold Mines, Fish, and Mercury Ingestion
Fréry et al. (p. 449) report mercury exposure from gold-mining and gold- washing activities in native Amerindians in French Guiana who consumed fish caught in the Maroni River. Based on the results of hair samples, 57% of the Amerindians exhibited mercury levels above the World Health Organization safety limit. All people over 1 year of age ate fish containing mercury above safety limits; 4 of 48 fish species accounted for 72% of the mercury ingested. (Also see Science Selections, p. A225)
Pfiesteria Targets Receptor in Rat Pituitary
Kimm-Brinson et al. (p. 457) identified a toxin (pPfTx) produced by Pfiesteria piscicida that is cytotoxic in a line of rat pituitary cells. The authors report that the cytotoxicity is mediated by a P2X7 receptor in nerve cells. This P2X7 receptor may cause chronic inflammation and the neurotoxicity attributed to this organism. (Also see Science Selections, p. A224)
Cold, Heat, and Mortality in the Dutch
Huynen et al. (p. 463) evaluated weather patterns and mortality records in the Netherlands from 1979 to 1997 and found that extremes in heat and cold mostly affected the elderly. Deaths during heat waves were ascribed to respiratory problems, while deaths during cold spells were mostly attributable to cardiovascular problems.
Organophosphate Pesticides Induce Rat Mammary Tumors
Using a rodent model, Cabello et al. (p. 471) determined that eserine, parathion, and malathion increased mammary cell proliferation in 44-day-old rats, decreased acetylcholinesterase activity, and ultimately resulted in mammary tumors after 28 months. The authors suggest that organophosphate pesticides influenced carcinogenesis by increasing cholinergic stimulation in mammary gland epithelium.
Biomass Combustion and Acute Respiratory Infections
Acute respiratory infections are a leading cause of disease that have been linked to pollutant exposure from domestic biomass fuels in developing countries. In a study in rural Kenya, Ezzati and Kammen (p. 481) found that acute respiratory infections increase in proportion to biomass combustion with particulates < 10 µm diameter but increase at a lower rate for exposures > 2,000 µg/m3. The authors urge that the consequences of this exposure-response relationship be considered when formulating international public health policies.
Correction is made on 7 June 2001.
Climate and Malaria in Colombia
Poveda et al. (p. 489) evaluated the relationship between climate and malaria and report that the malaria cases exhibit a strong annual cycle that is highly associated with the hydroclimatic cycle. Both cycles were consistently enhanced during El Niño, suggesting a phase-locking mechanism in the environmental, ecological, and entomological factors of the disease.
Urinary Biomarkers and 2,4-D in Foresters
Garry et al. (p. 495) analyzed chromosomal aberrations, reproductive hormones, and the frequency of gene rearrangement in herbicide applicators, and compared the biomarkers to urinary levels of 2,4-dichlorophenoxy acetic acid. Applicators with high herbicide exposure exhibited altered genomic stability that was reversible after 8 months.
Melatonin Hypothesis in Women
It has been hypothesized that increases in breast cancer in industrial societies are related to increased exposure to electric and magnetic fields (EMF) or high levels of light at night (LAN), which decreases melatonin levels and causes concomitant increases in estrogen. Graham et al. (p. 501) evaluated young women exposed at night to EMF and LAN. They found no effects on melatonin or estradiol after EMF exposure, and melatonin suppression but no estradiol alteration after LAN exposure, thus raising doubts about the melatonin hypothesis.
Data Reproducibility in Rodent Cancer Studies
Gottman et al. (p. 509) compared replicate chemical testing data from 121 rodent carcinogenicity assays obtained from either the U.S. government database or from the
general literature and report a 57% concordance. The authors suggest that the reproducibility of rodent cancer test data is less than expected and should be considered when developing structure-activity models or when making risk assessments.
Suppression of Macrophage Function by Diesel Exhaust
Yang et al. (p. 515) studied rat susceptibility to pulmonary infection by exposure to diesel exhaust particles. In exposed rats, Listeria lung infection was increased and development of T-cell-mediated immunity was impaired, as shown by reductions in the response of lung macrophages to produce antimicrobial oxidants. The authors suggest that these changes were due to the organic components of diesel exhaust as similar changes did not occur after carbon black exposure.
Arsenic Induction of DNA Strand Breaks
Li et al. (p. 523) report that arsenic at micromolar concentrations induced oxidative DNA damage in human lymphocytes after 2-hr exposure. Strand breaks were more slowly repaired in unstimulated cells than in phytohemagglutinin-stimulated cells, suggesting that there are either different amounts or activities of DNA repair enzymes in the proliferating and nonproliferating cells.
Maternal and Fetal Lead Exposure
Chuang et al. (p. 527) measured maternal blood and bone lead, environmental lead, and umbilical cord lead (as a measure of fetal lead) and determined used of lead-glazed ceramics in 615 pregnant women in Mexico. A model of the data suggested that the greatest influences on maternal plasma lead were bone lead stores, air lead exposure, and contaminated cookware. Measurement of plasma and bone lead helped to assess fetal lead exposure and its major sources. (Also see Science Selections, p. A224)
Pesticide Exposure among Migrant Workers
To collect data for needed research into the problems of migrant farm worker families, investigators should use culturally appropriate methods. McCauley et al. (p. 533) used a community-based approach to access information, and they found that azinphos methyl was a common residue in homes and that crowded living conditions enhance exposure risk for migrant children.
Possible Estuary-Associated Syndrome in Five Cases
Shoemaker and Hudnell (p. 539) present five cases that represent the spectrum of symptoms of possible estuary-associated syndrome (PEAS), a suspected neurotoxin-mediated illness. Symptoms, including headache, skin rash, diarrhea, cough, and fatigue, improved after patients were treated with cholestyramine. The authors recommend that research to identify health risks of single and repeated PEAS episodes should be conducted.
Last Updated: May 30, 2001