Environews
FOCUS | Waste Couture: Environmental Impact of the Clothing Industry
In today's global society, the increasingly rapid production and corresponding consumption of clothing have caused it to evolve into a disposable commodity. But the life span of the average piece of clothing is not always short or simple; many garments travel a winding path from beginning to end use, serving multiple functions throughout. Today's culture of "fast fashion" has led to unprecedented growth in the world's clothing supply. This article (p. A448) takes a look at how the initial production and resultant surplus of clothing are impacting the environment.
SPHERES OF INFLUENCE | Certified Coffee: Does the Premium Pay Off?
For millions of people dependent on coffee farming, the 1990s coffee crisis brought social and economic devastation, and forced many farmers to choose between immediate household needs and environmental destruction. Today, Fair Trade and other certification programs offer farmers a buffer against market fluctuations in exchange for proof of sustainable management. This article (p. A456) examines the question of whether certification is making a difference in the health of the forests and the lives of the people who produce certified coffee.
Commentary
POPULATION HEALTH | Forest for Trees
Gohlke and Portier (p. 1261) explored the relationship between current directions in human health research and environmental and public health policy. They suggest that there is a link between the continuing emphasis in biomedical research on individualized, therapeutic solutions to human disease and the increased reliance on individual choice in response to environmental and/or public health threats. The authors recommend that research programs be redirected to interdisciplinary and population-focused research that would support a systems approach to fully identifying the environmental factors that contribute to disease burden. This approach would make it possible to address the interactions between social, ecologic, and physical aspects of the environment and explicitly include these in the evaluation and management of health risks from environmental exposures.
Review
GENE REGULATION/GENE EXPRESSION | Gene by Environment Interactions and Disease
Health or disease is shaped for all individuals by interactions between their genes and their environment. Current studies are exploring how the environment changes gene expression and how this can lead to disease. Edwards and Myers (p. 1264) searched the Web of Science and references of relevant publications to understand the diversity of gene regulatory mechanisms affected by environmental exposures with disease implications. These studies indicate that disease risk is best predicted in the context of genetic and environmental factors in combination.
Research
POPULATION HEALTH | Depuration of PBDEs and PCBs in Breast Milk
Rates of depuration (loss) of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) from mothers during lactation affect infant exposure to chemicals during breast-feeding and also fetal and lactational transfers during subsequent pregnancies. Hooper et al. (p. 1271) estimated depuration rates of PBDEs and PCBs using serial samples of breast milk collected from first-time mothers (primiparae). Their results indicate that PBDEs and PCBs are not substantially reduced in primiparae after 6 months of breast-feeding. Consequently, the fetal and lactational exposures for a second child may not be markedly lower than those for the first.
BONE AND CARTILAGE | Pb Induces Chondrogenesis
Skeletal growth is stunted in lead-exposed children. Because chondrogenesis is a seminal step during skeletal development, elucidating the impact of Pb on this process is the first step toward understanding the mechanism of Pb toxicity in the skeleton. Zuscik et al. (p. 1276) tested the hypothesis that Pb alters chondrogenic commitment of mesenchymal cells and assessed the effects of Pb on various signaling pathways. The in vitro and in vivo induction of chondrogenesis by Pb likely involves modulation and integration of multiple signaling pathways such as TGF-β, BMP, AP-1, and NF-κB.
Also see Science Selections, p. A461
RISK CHARACTERIZATION | Atmospheric Pollution and Term Birth Weight
Previous studies have indicated that particulate matter levels during pregnancy could be associated with birth weight. Road traffic is a major source of fine particulate matter (≤ 2.5 µm in aerodynamic diameter; PM2.5). Slama et al. (p. 1283) characterized the influence of maternal exposure to atmospheric pollutants from road traffic and urban activities on offspring term birth weight. The study included women from a birth cohort who delivered a nonpremature baby with a birth weight > 2,500 g in the Munich, Germany, metropolitan area. Increases in PM2.5 levels and PM2.5 absorbance were associated with decreases in term birth weight, suggesting that traffic-related air pollutants influence birth weight.
TOXICOLOGY | Carcinogenicity of Aspartame
Aspartame (APM) has been reported to be a multipotent carcinogenic agent when various doses are administered with feed to Sprague-Dawley rats from 8 weeks of age throughout life. To better quantify the carcinogenic risk of APM, Soffritti et al. (p. 1293) studied groups of 70–95 male and female Sprague-Dawley rats administered APM (2,000, 400, or 0 ppm) with feed from prenatal day 12 until natural death. The results confirm the previous report of APM's multipotential carcinogenicity at a dose level close to the acceptable daily intake for humans. The study also demonstrates an increase in carcinogenic effects of APM when life-span exposure begins during fetal life.
Also see Science Selections, p. A460
METABOLISM | Half-Life of Perfluoroalkyl Acids in Humans
Perfluorooctanesulfonate (PFOS), perfluorohexanesulfonate (PFHS), and perfluorooctanoate (PFOA) have been reported in humans and wildlife, and pharmacokinetic differences have been observed in laboratory animals. Olsen et al.(p. 1298) estimated the elimination half-life of PFOS, PFHS, and PFOA in human serum from 26 retired fluorochemical production workers who had no additional occupational exposure. Periodic blood samples collected over 5 years were analyzed with HPLC-mass spectrometry. Data indicate that humans have a long half-life of serum elimination of PFOS, PFHS, and PFOA. Differences in species-specific pharmacokinetics may be due, in part, to a saturable renal resorption process.
NEURODEVELOPMENT | Ameliorating Chlorpyrifos Neurotoxicity
Developmental neurotoxicity of organophosphate involves multiple mechanisms converging on neural cell replication and differentiation. Slotkin et al. (p. 1306) evaluated mechanisms contributing to the adverse effects of chlorpyrifos (CPF) on DNA synthesis, cell number and size, and cell signaling mediated by adenylyl cyclase (AC) in PC12 cells. Results show definitive contributions of cholinergic hyperstimulation, oxidative stress, and interference with AC signaling in the developmental neurotoxicity of CPF.
Also see Science Selections, p. A461
REPRODUCTIVE HEALTH | Prenatal DES Exposure and Secondary Sex Ratio
Diethylstilbestrol (DES), a synthetic estrogen widely prescribed to pregnant women during the mid-1900s, is a potent endocrine disruptor. Previous studies have suggested an association between endocrine-disrupting compounds and secondary sex ratio. Wise et al. (p. 1314) used generalized estimating equations to estimate odds ratios and 95% confidence intervals for the relation of in utero DES exposure to sex ratio (proportion of male births) among female participants from the National Cancer Institute DES Combined Cohort Study. Results did not vary appreciably by maternal age, parity, cohort, or infertility history. Overall, the authors found no association between in utero DES exposure and secondary sex ratio; however, they found a significant increase in the proportion of male births among women first exposed to DES earlier in gestation and to a higher cumulative dose.
REPRODUCTIVE HEALTH | PCBs and Critical Windows
Few data are available on concentrations of polychlorinated biphenyls (PCBs) over critical windows of human reproduction and development, inclusive of the periconception window. Bloom et al. (p. 1320) measured changes in PCB concentrations from preconception to pregnancy, through pregnancy, or after a year without becoming pregnant in 79 women planning pregnancies; these women were prospectively enrolled and followed for up to 12 menstrual cycles of attempting pregnancy. Blood samples were analyzed for 76 PCB congeners. Results suggest that PCB concentrations may change during the periconception interval, calling into question the stability of persistent compounds during this critical window.
RESPIRATORY DISEASE | Cell Response to Indoor Dust
Airway toxicity of indoor dust is not yet sufficiently understood. Riechelmann et al. (p. 1325) examined the effects of indoor dust on human monocyte, epithelial, and lymphocyte cell lines to obtain a comprehensive and intelligible outline of the transcriptional response; correlate differential transcription with cellular protein secretion; identify cell line–specific features; and search for indoor dust–specific responses. Results showed that monocytes are particularly responsive to indoor dust. The authors observed a classical, T-helper 1-dominated immune response suggesting bioorganic contaminants as relevant effectors in indoor dust.
ENDOCRINE SYSTEM | Smoking, Perchlorate, and Thyroid Hormones
Perchlorate, at commonly occurring exposure concentrations, may decrease thyroid hormone levels in some women. Decreases in thyroid hormone seen with perchlorate exposure could be even greater in people with concomitant exposure to agents such as thiocyanate that may affect the thyroid by mechanisms similar to those of perchlorate. Steinmaus et al. (p. 1333) used data from the National Health and Nutrition Examination Survey to assess the impact of smoking and thiocyanate on the relationship between urinary perchlorate and serum thyroxine and thyroid-stimulating hormone. Results suggest that thiocyanate in tobacco smoke and perchlorate interact in affecting thyroid function and that this effect can take place at commonly occurring perchlorate exposures. Because agents other than tobacco smoke might cause similar interactions, further research on these agents could help identify people who are particularly susceptible to perchlorate.
NANOTECHNOLOGY | Tissue Kinetics of QD705
Quantum dots (QDs) are autoflourescent semiconductor nanocrystals that can be used for in vivo biomedical imaging. However, little is known about their in vivo disposition and health consequences. Yang et al. (p. 1339) assessed the blood and tissue kinetics of QD705 in mice for up to 28 days after a single intravenous injection of 40 pmol. The primary method of quantification of QD705 was inductively coupled plasma–mass spectrometry measurement of cadmium. Fluorescence light microscopy revealed the localization of QD705 in tissues. The authors determined that QD705 has a very long half-life in the body, potentially weeks or even months, and its health consequences should be investigated further.
ENVIRONMENTAL JUSTICE | Race, Wealth, and Solid Waste
There is some concern that solid waste facilities in North Carolina may be disproportionately located in poor communities and in communities of color and that solid waste facilities negatively impact the health of host communities. Norton et al. (p. 1344) conducted a statewide analysis of the location of solid waste facilities in relation to community race and wealth using census block groups to obtain racial and economic characteristics, and abstracting information on solid waste facilities from permit records. Using logistic regression to compute prevalence odds ratios for 2003 and Cox regression to compute hazard ratios of facilities obtaining new permits between 1990 and 2003, the authors concluded that solid waste facilities are disproportionately located in communities of people of color and low wealth.
REPRODUCTIVE HEALTH | Hormonally Induced Reproductive Tumors
The National Toxicology Program (NTP) is currently reviewing its research portfolio as part of its efforts to implement the NTP Roadmap to achieve the NTP Vision for the 21st century. Thayer and Foster (p. 1351) report on a workshop, "Hormonally Induced Reproductive Tumors—Relevance of Rodent Bioassays," that was organized to determine the adequacy and relevance to human disease outcome of rodent models currently used in the 2-year bioassay for four types of hormonally induced reproductive tumors (ovary, mammary gland, prostate, and testis). For some types of tumors such as prostate, no adequate animal models exist, and for others such as ovary, the predominant tumors in humans are of different cellular origins than those induced by chemicals in rodents. It was recommended that the NTP consider modifying its testing protocols and/or using alternative models to improve sensitivity.
Also see Science Selections, p. A460
POPULATION HEALTH | Role of Lighting in Disease
Light, including artificial light, has a range of effects on human physiology and behavior and can therefore alter human physiology when inappropriately timed. Changes in light–dark exposure shift the timing of the circadian system, desynchronizing internal rhythms from both the external environment and internally. Stevens et al. (p. 1357) report on a workshop in which participants noted three broad areas of research effort that should be addressed: a) the basic biophysical and molecular genetic mechanisms for phototransduction for circadian, neuroendocrine, and neurobehavioral regulation; b) the possible physiologic consequences of disrupting these circadian regulatory processes on, for example, hormone production and normal and neoplastic tissue growth dynamics; and c) effects of light-induced physiologic disruption on disease occurrence and prognosis, and how prevention and treatment could be improved by application of this knowledge.
Children's Health
EXPOSURE ASSESSMENT | Error and Bias in Determining Exposure Potential Using GIS
The widespread availability of powerful tools in commercial geographic information system (GIS) software has made address geocoding a widely employed technique in spatial epidemiologic studies. Zandbergen and Green (p. 1363) performed a case study of Orange County, Florida, in which they determined the positional error of geocoding of school locations through comparisons with a parcel database and digital orthophotography using four different geocoding techniques. Results indicate that the positional error in geocoding of schools is substantial and that bias and error in analyzing proximity to major roads is unacceptably large at distances of < 500 m, More accurate alternatives need to be considered.
NEURODEVELOPMENT | Arsenic and Cognitive Performance in Children
Previous studies have suggested an effect of high arsenic concentration on cognitive and neurobehavioral function in humans. To identify demographic and nutritional factors associated with arsenic exposure and the influence of this exposure on cognitive function in school-age children, Rosado et al. (p. 1371) recruited children 6–8 years of age living within 3.5 km of a metallurgic smelter complex in Torreon, Mexico, to participate in a cross-sectional evaluation. Of these, 591 had complete anthropometry; measurement of iron and zinc concentrations in serum, lead concentration in blood, and arsenic in urine (UAs); and 557 completed several cognitive performance tests. The authors found a significant inverse association between UAs and scores on several cognitive performance tests. Boys excreted significantly more UAs and were affected in different cognitive areas than girls. Arsenic contamination affected children's cognitive development, independent of any effect of lead.
HEALTH POLICY | Children's Environmental Health Indicators
Pond et al. (p. 1376) report on a working group coordinated by the World Health Organization that was convened to develop a set of indicators to protect children's health from environmental risks and to support current and future European policy needs. The group developed a core set of 29 indicators for implementation plus an extended set of 8 additional indicators for future development, focusing on exposure, health effects, and action. These indicators cover most of the priority topic areas specified in the Children's Environment and Health Action Plan for Europe (CEHAPE); this effort is part of the Global Initiative on Children's Environmental Health Indicators, launched at the World Summit on Sustainable Development in 2002.
