Environews
Centers for Oceans and Human Health
The NIEHS and the National Science Foundation announce the establishment of four new centers to study the ecology, oceanography, and genetics of marine pathogens, described in this month's NIEHS News (p. A468). Center researchers will look at the many ways the oceans affect human health, in both beneficial and adverse ways.
More Than Just Fish in the Sea
Ask any passerby what "bounty of the sea" means, and you'll probably hear a rapturous description of a favorite seafood dish. But the oceans offer us much more than just food. The Focus (p. A472) examines a few of the most notable benefits we can gain from the oceans--provided we take seriously our need to be responsible stewards of the sea.
The Inside Scoop: EPA Risk Assessment
The Spheres of Influence (p. A482) reviews a recent staff paper published by the Environmental Protection Agency and developed with the input of hundreds of staffers that gives an insider's view of what's going both right and wrong with the agency's risk assessment process.
Crustacean Sensation
This month's Innovations (p. A486) describes the biomimetic RoboLobster, a robot equipped with algorithms that mimic a lobster's keen sense of smell. Someday RoboLobster may be able to track marine pollutants, sniff out unexploded ordnance, and perform other underwater detective work.
Research
Antimony an Unlikely Confounder in Pabna, Bangladesh
Recent in vitro studies suggest a potential role for antimony as a confounder in human health studies of arsenic in drinking water. McCarty et al. (p. 809) measured tube-well water concentrations of antimony and arsenic in Pabna, Bangladesh. They analyzed 245 tube-well water samples for arsenic and antimony concentrations: the arsenic concentrations ranged from < 1 to 747 µg/L, and the antimony concentrations were < 1 µg/L.
A Tale of Two Diesels
Two different samples of diesel exhaust particles (DEPs) have been used by toxicologists interested primarily in cancer/genotoxicity or noncancer (e.g., pulmonary inflammation and asthma end points). On the basis of the differences between these standard samples, Arey (p. 812) points out the need for more cooperation among toxicologists, analytical chemists, atmospheric chemists, and automotive and combustion engineers to provide comprehensive health risk assessments for more diverse types of DEPs and ambient samples.
Mutagenicity of DEPs
Many pulmonary studies of diesel exhaust particles (DEPs) have used an automobile-generated sample (A-DEP) with unreported mutagenicity. In contrast, many mutagenicity studies of DEPs have used a forklift-generated sample (SRM 2975) evaluated in few pulmonary studies. DeMarini et al. (p. 814) evaluated mutagenicity of both A-DEPs and SRM 2975 in Salmonella coupled to a bioassay-directed fractionation. The A-DEPs were more mutagenic than SRM 2975, having 227 times more PAH-type and 8-45 times more nitroarene-type mutagenic activity. The results highlight the need for more thorough studies on a variety of representative DEP samples. (Also see Science Selections, p. A490)
Comparative Pulmonary Toxicity of Diesel
An automobile-derived diesel exhaust particle (A-DEP) sample and the forklift-generated standard reference material (SRM 2975) predominate in health effects research. Singh et al. (p. 820) combined physical and chemical analyses of both A-DEP and SRM 2975 with pulmonary toxicity testing in mice. A-DEP had > 10 times more extractable organic material and less than one-sixth elemental carbon compared to SRM 2975. Both produced mild acute lung injury. A-DEP induced macrophage influx and activation, whereas SRM 2975 enhanced polymorphonuclear cell inflammation. A-DEP increased interleukin (IL)-6, tumor necrosis factor-*, macrophage inhibitory protein-2, and the Th2 cytokine IL-5, whereas SRM 2975 only induced IL-6. (Also see Science Selections, p. A490)
PCBs, Thyroid Hormones, and Retinol in Polar Bears
The polar bear (Ursus maritimus) is the apex predator in the Arctic food web. Braathen et al. (p. 826) studied the relationships between polychlorinated biphenyls (PCBs) and thyroid hormones (THs) and retinol in two groups of female polar bears with and without cubs of the year and in a group of males. PCBs did not affect the retinol in any group. PCBs affected five TH variables in the female polar bears but only two TH variables in males, suggesting that female polar bears may be more susceptible to TH-related effects of PCBs.
Questionnaire Prediction of Pet and Cockroach Allergens
Gehring et al. (p. 834) assessed the accuracy of questionnaires in predicting allergen concentrations in house dust. The allergen content of house dust was measured by ELISA and related to questionnaire information on cat and dog ownership and the presence of cockroaches. Knowledge of past pet ownership can improve pet allergen exposure assessment by means of questionnaires; however, for epidemiologic purposes, measured concentrations of allergens are necessary.
Cellular and Humoral Immune Abnormalities in Gulf War Veterans
Vojdani and Thrasher (p. 840) examined 100 symptomatic Gulf War veteran patients and 100 controls using immunologic assays. Several immune alterations consistent with exposure to environmental factors were detected 2-8 years after Gulf War participation in patients compared to controls. The patients also had significantly greater titers of antibodies to tested viruses than the controls (p < 0.001). Results suggest that Gulf War syndrome is a multifaceted illness with immune function alterations that may be associated with chronic fatigue syndrome.
Control Variability and Low-Dose Endocrine-Disruptor Toxicity
Weak low-dose endocrine-disrupting effects in the rat uterotrophic assay have proven difficult to confirm across independent laboratories. Ashby et al. (p. 847) provide an analysis of bisphenol A and other reported instances of weak or low-dose endocrine effects based on ordering experiments according to decreasing control uterine weight. Results indicate that variability among controls provides a major obstacle to data interpretation and confirmation. The authors make recommendations on experimental design.
Organochlorines and Non-Hodgkin's Lymphoma
Quintana et al. (p. 854) examined the relationship between non-Hodgkin's lymphoma (NHL) and organochlorine pesticides using data collected between 1969 and 1983 in the U.S. Environmental Protection Agency's National Human Adipose Tissue Survey. From the original study population, 175 NHL cases were identified and matched to 481 controls. The organochlorine pesticide residue heptachlor epoxide was associated with NHL, as were the highest levels of dieldrin, oxychlordane, p,p´-DDE, and ß-benzene hexachloride. Given the persistence of pesticides in the environment, these findings are still relevant.
E2 and Cd Toxicity in Amphibian Embryos
Environmental species may be exposed to multiple toxicants with unexpected combined adverse effects. Fridman et al. (p. 862) exposed South American toad (Bufo arenarum) embryos to 17ß-estradiol alone and in combination with cadmium. The results suggest that estrogenic endocrine disruptors enhance the toxic effect of cadmium in amphibian embryos.
Individual Response to Styrene Exposure
Vodicka et al. (p. 867) examined the effect of occupational exposure to styrene on frequencies of chromosomal aberrations and binucleated cells with micronuclei, single-strand DNA breaks in peripheral blood lymphocytes, and DNA repair in plastics workers and controls. They found no clear relationship between styrene exposure and chromosomal aberration. Binucleated cells with micronuclei were moderately related to styrene exposure. There was a negative correlation between exposure and single-strand breaks. A positive correlation between exposure and DNA repair suggests that repair pathways may be induced by styrene exposure.
Particles Induce Ventilatory Abnormalities
Preexistent cardiopulmonary disease in humans enhances susceptibility to the adverse effects of ambient particulate matter. Gardner et al. (p. 872) examined effects of residual oil fly ash (ROFA) on ventilatory function in a rat model of pulmonary hypertension induced by monocrotaline (MCT). ROFA exposure induced histologic changes and abnormalities in several ventilatory parameters, many of which were enhanced by MCT treatment.
Ultrafine Particle Deposition in Asthma
Ambient ultrafine air particles (diameter < 100 nm) may contribute to the health effects of particulate matter. Chalupa et al. (p. 879) examined the deposition of ultrafine carbon particles with a count median diameter of 23 nm and a geometric SD of 1.6 in asthmatic subjects during spontaneous breathing at rest and during exercise. The number deposition fraction increased as particle size decreased and also during exercise. Experimental deposition data exceeded model predictions during exercise. The deposition at rest was greater in these subjects with asthma than in previously studied healthy subjects.
Risks Associated with Chemically Contaminated Shellfish
Shellfish accumulate chemical contaminants and may present a risk for consumers. Gagnon et al. (p. 883) surveyed 162 harvesters and shellfish for 10 metals, 22 polycyclic aromatic hydrocarbons, 14 polychlorinated biphenyls (PCBs), and 10 chlorinated pesticides. Cancer and noncancer risks were subsequently evaluated for four consumption scenarios based on survey and published results. Inorganic arsenic and PCBs were present in sufficient concentration to lead to cancer risks exceeding the level considered acceptable for environmental exposure in each of the four scenarios. (Also see Science Selections, p. A491)
Breast Cancer Risk and GIS-Assessed Pesticide Exposure
Many pesticides mimic estrogen, a known breast cancer risk factor. Brody et al. (p. 889) used geographic information system (GIS) technology to assess historical exposures to banned and current-use pesticides in a population-based case-control study of women diagnosed with breast cancer in 1988-1995 and controls. There was no overall pattern of association between pesticide use and breast cancer. There were modest increases in risk (adjusted odds ratios < 1.8) associated with aerial application of persistent pesticides on cranberry bogs and less-persistent pesticides applied on trees or for agriculture.
Intersex in White Perch
Kavanagh et al. (p. 898) collected fish in 1998 from the Cootes Paradise region of western Lake Ontario, Canada, to evaluate gonadal abnormalities in the young of the year. They observed no gonadal abnormalities in goldfish (Carassius auratus), common carp (Cyprinus carpio), gizzard shad (Dorosoma cepedianum), brown bullhead (Ictalurus ameiurus), pumpkinseed (Lepomis gibbosus), or bluegill (Lepomis macrochirus). However, intersex gonads were observed in white perch (Morone americana). Analysis of plasma collected in spring 2002 from male adult white perch in Cootes Paradise revealed high concentrations of vitellogenin, indicating exposure to estrogenic compounds.
Effects of Dioxin on Rat Exocrine Pancreas
The effect of chronic exposure to dioxin and dioxin-like compounds on the pancreas in female rats was evaluated by Nyska et al. (p. 903). Animals were gavage-treated for up to 2 years with TCDD, 3,3´,4,4´,5-pentachlorobiphenyl (PCB-126), 2,3,4,7,8-pentachlorodibenzofuran (PeCDF), or a toxic-equivalency-factor (TEF) mixture of these agents. Low incidences, but higher than those in the historical database, of pancreatic acinar adenoma and carcinoma were seen in TCDD, PeCDF, and TEF-mixture groups. Results indicate that the pancreatic acini are target tissues for dioxin and certain dioxin-like compounds.
Environmental Medicine
Mercury Exposure Aboard an Ore Boat
Mercury is used in the merchant marine industry in ballast monitors. Roach and Busch (p. 910) present the cases of two maritime interns exposed to mercury vapor after spilling a mercury bottle in an enclosed storeroom. One intern with initial serum mercury of 4 ng/mL suffered transient clinical intoxication that resolved after removal from the environment, showering, and discarding all clothing. The other intern had an initial mercury level of 11 ng/mL that continued to rise to a maximum of 188.8 ng/mL, leading to hospitalization. Continued exposure due to contaminated boots was presumed to be the cause.
Pesticide Testing in Humans: Ethics and Policy
Pesticide manufacturers have increasingly tested pesticides in human volunteers. There are no required ethical guidelines, no governmental oversight is exercised, and there are no procedures in place for the protection of subjects. Oleskey et al. (p. 914) discuss results of an expert workshop convened by the Center for Children's Health and the Environment of the Mount Sinai School of Medicine to examine issues involved in the testing of pesticides in humans and the use of human data in standard setting. The authors provide ethical and public policy recommendations.
Children's Health
Disinfection By-products and Fetal Development
Epidemiologic studies of disinfection by-products have used total trihalomethane (TTHM) as a surrogate for maternal exposure during pregnancy. Wright et al. (p. 920) examined the effect of town-average concentrations of TTHM and additional exposure metrics on mean birth weight, mean gestational age, small for gestational age (SGA), and preterm delivery. Birth weight reductions were detected for maternal THM exposures > 90th percentile, chloroform exposures > 20 mg/L, and TTHM exposures > 40 mg/L. There was also evidence of an exposure-response effect for THMs on SGA. (Also see Science Selections, p. A490)
Breast Milk Lead in Relation to Maternal Blood and Bone
Mobilization of maternal bone lead has been suggested as a source of breast milk lead reported in women with no current exposure. Ettinger et al. (p. 926) quantified the relationship between maternal blood and bone lead levels and breastfeeding status among lactating women in Mexico City. Breast milk lead correlated with umbilical cord and maternal blood lead at delivery and with maternal blood lead and patella lead at 1 month postpartum. Among women with relatively high lifetime exposure, levels of lead in breast milk are low, and influenced by current exposure and redistribution of accumulated bone lead.
FEV1 in Asthmatic Children and Airborne Particulate Matter
Exposure to particulate matter (PM) air pollution exacerbates children's asthma. Delfino et al. (p. 932) examined the relationship of temporal changes in percent-predicted forced expiratory volume in 1 sec (FEV1) among 9- to 17-year-old asthmatics to personal continuous PM exposure and 24-hr average PM measured at home and at central sites. They found inverse associations of FEV1 with increasing PM exposure in the 24 hr before the FEV1 maneuver and in multiday PM averages. Stronger associations were found for multiday moving averages of PM.
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Last Updated: May 14, 2004