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31.
Bergkvist C Aune M Nilsson I Sandanger TM Hamadani JD Tofail F Oyvind-Odland J Kabir I Vahter M 《Chemosphere》2012,88(7):784-790
In low-income countries, the use of some organochlorine pesticides is still common in order to increase food production. Monitoring the chemical exposure is an important step in risk-reducing strategies. This is the first study to report concentrations of organochlorines in breast milk of women from Bangladesh where farming is the main income source.Organochlorines such as p,p′-DDT, o,p′-DDT, p,p′-DDE, p,p′-DDD (i.e., ∑DDT), HCB, α-, β- and γ-HCH, trans-chlordane, cis-chlordane, oxy-chlordane, trans-nonachlor, cis-nonachlor, mirex and polychlorinated biphenyls (CB 28, 52, 99, 101, 105, 114, 118, 123, 128, 138, 141, 149, 153, 156, 157, 163, 167, 170, 180, 183, 187, 189, 194) were analyzed in breast milk collected in 2002 from 72 first-time mothers (median age 20 years) living in the rural area Matlab, Bangladesh.While the concentrations of PCBs and many of the pesticides were low, the concentrations of p,p′-DDT and its metabolite p,p′-DDE were high (median 349 and 1645 ng g−1 lipid, respectively) in comparison to other countries. The median value of ∑DDT was 2123 ng g−1 lipid. The estimated daily exposure to p,p′-DDT, p,p′-DDE and ∑DDTs was 10, 30 and 42 μg kg−1 body weight, respectively, in 3 months old infants. The p,p′-DDE/p,p′-DDT ratio ranged from 1 to 23, where 58% of the mothers had a ratio below 5 indicating recent or ongoing DDT exposure.This study reports infant exposure and maternal body burden of organochlorines through breast milk. Although the findings give no reason to limit breast-feeding, it is essential to identify the main exposure sources and find means to decrease the exposure. 相似文献
32.
The resources sector in Australia makes a major contribution to the national economy, and underpins employment and population in the mining and mineral processing towns. For those towns, rapid growth in employment can generate particular pressures in local housing markets because of the relatively large size of the industry and the small housing stocks involved. Through a case study of Gladstone, the study provides a dynamic five-step population and housing model, to estimate short to medium term mining impacts of major resource developments. The model includes both the direct and indirect labour force generated by new resource sector developments and their flow-on effects on population increases. Sensitivity testing has allowed for different levels of resource development, employment multipliers and labour inflows. Three different approaches have then been applied to predict the housing price impacts of the expected population growth. 相似文献
33.
In this study, fertilized Japanese medaka (Oryzias latipes) embryos were exposed from fertilization to 5 d post-hatch using static non-renewal assays to aqueous suspensions of titanium dioxide nanoparticles (nTiO2) ranging in nominal concentrations between 0 and 14 μg mL−1. The average size of the nTiO2 in the stock solution before addition to the test treatments was 87 nm (±14 nm). TiO2 materials accumulated in a concentration dependent manner on the chorionic filaments of developing medaka embryos with evidence of pericardial edema occurring during embryo development. However, no significant (p > 0.05) increases in mortality relative to control treatments were observed for the nTiO2 exposed embryos. A concentration dependent increase in cumulative percent hatch was observed at 11 d, indicating that exposure to increasing concentrations of nTiO2 resulted in the premature hatch of medaka embryos. Post-hatch, a significant proportion of sac fry from the nTiO2 exposure groups exhibited moribund swimming behavior and these individuals also experienced greater mortality at 15 d post-hatch. Combined, these results demonstrate that exposure to nTiO2 can impact the development of early life stages of fish. 相似文献