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China's water pollution by persistent organic pollutants
2012
Bao, Lian-Jun | Maruya, Keith A. | Snyder, Shane A. | Zeng, E. Y. (Eddy Y.)
Available data were reviewed to assess the status of contamination by persistent organic pollutants (POPs), including organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs), perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA), in drinking water sources and coastal waters of China. The levels of POPs in China's waters were generally at the high end of the global range. A comparison of China's regulatory limits indicated that PCBs in rivers and coastal water may pose potential human health risk. Occurrence of DDTs in some rivers of China may also pose health risk to humans using the regulatory limits of DDTs recommended by the European Union. Future monitoring of POPs in China's waters should be directed towards analytes of concern (e.g. PCBs and PCDD/Fs) and to fill data gaps for analytes (e.g. PBDEs, PCDD/Fs, and chlordane) and in watersheds/regions (e.g. West China) where data are scarce.
Показать больше [+] Меньше [-]Parent and halogenated polycyclic aromatic hydrocarbons in rice and implications for human health in China
2012
Ding, Chao | Ni, Hong-Gang | Zeng, Hui
Rice is the staple food for approximate two thirds of the Chinese population. However, human exposure to parent and halogenated polycyclic aromatic hydrocarbons (PAHs) via rice consumption is still not clear for Chinese people so far. The goals of this work are to assess human exposure to PAHs and halogenated PAHs (HPAHs) via rice ingestion and the cancer risk for Chinese population. 16 PAHs and eight HPAHs were determined in rice samples collected from 18 provinces in China. In general terms, the general population in China was exposed to higher levels of PAHs via rice ingestion in comparison to that via cereals for other countries. The cancer risk values induced by exposure to PAHs and HPAHs for male and female on each age group were between the priority risk level (10⁻⁴) and the acceptable risk level (10⁻⁶). Children faced the highest cancer risk, followed by adolescents and adults.
Показать больше [+] Меньше [-]Multicorrelation models and uptake factors to estimate extractable metal concentrations from soil and metal in plants in pasturelands fertilized with manure
2012
Lopes, Carla | Herva, Marta | Franco-Uría, Amaya | Roca, Enrique
Environmental risk assessment (ERA) is a useful methodology to estimate the possible adverse effects to human health due to contaminants exposure. In the case of agricultural scenarios, this method requires knowing the concentrations of contaminants in soil solution and vegetation, among other parameters. This study aimed to develop multicorrelation models to estimate metal extractable from soil as a function of total metal concentration in soil and soil properties in a cattle manure application scenario. It also aimed to estimate metal concentrations in plant by soil–plant uptake factors (UF). All the multicorrelation models obtained were significant, ranging R² values from 0.44 for Cd to 0.92 for Cu. Soil–plant UF were an adequate method for the estimation of metal concentration in plant, since the relationship between the soil–plant UF and the extractable metal concentration from soil was significantly described by a power model, for all the heavy metals.
Показать больше [+] Меньше [-]Does consumption of leafy vegetables grown in peri-urban agriculture pose a risk to human health?
2012
Nabulo, G. | Black, C.R. | Craigon, J. | Young, S.D.
Concentrations of potentially toxic elements were measured in soils and five contrasting tropical leafy vegetables grown in a replicated field trial at five contaminated urban agriculture sites in Kampala City, Uganda. Soil contamination at each site could be tentatively ascribed to known waste disposal practices. There was considerable variation in metal uptake between vegetable types. Washing leafy vegetables reduced chromium and lead concentrations but exogenous contamination of leaves also depended on vegetable type, with Gynandropsis gynandra L. showing a marked tendency to accumulate Pb and Cr. For the worst case scenario of children consuming unwashed vegetables, some metal ‘hazard quotient’ (HQ) limits (1.0) were violated at four of the five sites studied. For the 25 ‘site-vegetable’ combinations assessed, the HQ for Pb exceeded 1.0 in 36% of cases. A vegetable-specific site screening tool based on soil extraction with 0.01M CaCl₂ and extrapolation to provide HQ values was assessed.
Показать больше [+] Меньше [-]Assessment of polyaromatic hydrocarbon degradation by potentially pathogenic environmental Vibrio parahaemolyticus isolates from coastal Louisiana, USA
2012
Smith, Conor B. | Johnson, Crystal N. | King, Gary M.
A presumed Vibrio parahaemolyticus isolate from Chesapeake Bay, Maryland, USA was previously reported to grow on phenanthrene, a polyaromatic hydrocarbon (PAH) found in crude oil. Following the Deepwater Horizon oil spill in the Gulf of Mexico, concerns were raised that PAH-degrading V. parahaemolyticus could increase in abundance, leading to elevated risks of disease derived from shellfish consumption. To assess this possibility, we examined responses to naphthalene and phenanthrene of 17 coastal Louisiana environmental V. parahaemolyticus isolates representing five distinct genotypes. Isolates were obtained immediately after the spill began and after oil had reached the Louisiana coast. None of the isolates grew on or oxidized either substrate and a naphthalene degradation product, 1-naphthol, substantially inhibited growth of some isolates. The use of PAH by V. parahaemolyticus is unusual, and an increase in human health risks due to stimulation of V. parahaemolyticus growth by oil-derived PAH under in situ conditions appears unlikely.
Показать больше [+] Меньше [-]Grounded or submerged bulk carrier: The potential for leaching of coal trace elements to seawater
2012
Lucas, Steven Andrew | Planner, John
This study investigates the potential for leaching of coal trace elements to seawater from a grounded bulk carrier. The coal type and ecological scenario was based on the grounding of the “Shen Neng” (April 2010) at Douglas Shoal located within the Great Barrier Reef (Queensland, Australia). The area is of high ecological value and the Queensland Water Quality Guidelines (2009) provided threshold limits to interpret potential impacts. Coal contains many trace elements that are of major and moderate concern to human health and the environment although many of these concerns are only realised when coal is combusted. However, “unburnt” coal contains trace elements that may be leached to natural waterways and few studies have investigated the potential ecological impact of such an occurrence. For example, coal maritime transport has increased by almost 35% over the last five reported years (Jaffrennou et al., 2007) and as a result there is an increased inherent risk of bulk carrier accidents. Upon grounding or becoming submerged, coal within a bulk carrier may become saturated with seawater and potentially leach trace elements to the environment and impact on water quality and ecological resilience. The worst case scenario is the breakup of a bulk carrier and dispersal of cargo to the seafloor.
Показать больше [+] Меньше [-]Overview of the 20th century impact of trace metal contamination in the estuaries of Todos os Santos Bay: Past, present and future scenarios
2012
Hatje, Vanessa | Barros, Francisco
This paper discusses the distribution patterns of trace metals in sediments and suspended particulate matter (SPM) in the three main estuaries of the Todos os Santos Bay (BTS), Brazil, during dry and rainy seasons. Data available up to 2012 was also reviewed to assess the status of contamination. For most elements, metal concentrations in sediments decreased from the tidal limits to the lower estuary. Metals in SPM presented more complex distributions along the salinity gradient. Metal variability between rainy and dry conditions was only significant for SPM data. Of the BTS estuaries, the levels of Cd, Zn, Pb and Cu are highest in the Subaé estuary, and they seem to be promoting harmful biological effects in macrofauna, and also may pose potential human health risks. Despite the evidence of important localized contamination, much of the data compiled indicates that the bay and its estuaries are still relatively preserved.
Показать больше [+] Меньше [-]Trace elements in two marine fish species during estuarine residency: Non-essential versus essential
2012
Mieiro, C.L. | Coelho, J.P. | Pacheco, M. | Duarte, A.C. | Pereira, M.E.
Trace element levels in fish are of particular interest, owing the potential risk to human health. In accordance, juveniles of Dicentrarchus labrax and of Liza aurata were sampled and arsenic, cadmium, chromium, selenium and zinc were determined in the muscle. The levels of trace elements in muscle demonstrated to be similar for both species and sites, with the exception of selenium levels at reference, which seemed to be higher in D. labrax. Moreover, apart from arsenic levels in muscle, all elements were in conformity with the existent regulatory guidelines for fish consumption. The dietary intake of each element was also calculated, with arsenic and selenium showing intakes above the recommended dietary allowances. Nevertheless, no arsenic speciation was carried out and thus no accurate risk evaluation could be established. Additionally, selenium levels never exceeded the dietary allowances more than five times, which are considered safe.
Показать больше [+] Меньше [-]Chesapeake Bay nutrient pollution: Contribution from the land application of sewage sludge in Virginia
2012
Land, Lynton S.
Human health concerns and the dissemination of anthropogenic substances with unknown consequences are the reasons most often given why disposal of municipal sewage sludge in landfills or using the organic waste as biofuel is preferable to land application. But no “fertilizer” causes more nitrogen pollution than sludge when applied according to Virginia law. Poultry litter is the only other “fertilizer” that causes more phosphorus pollution than sludge. Cost savings by the few farmers in Virginia who use sludge are far less than the costs of the nitrogen pollution they cause. A ban on the land application of all forms of animal waste is very cost-effective and would reduce Chesapeake Bay nutrient pollution by 25%.
Показать больше [+] Меньше [-]Pollutant impacts to Cape Hatteras National Seashore from urban runoff and septic leachate
2012
Mallin, Michael A. | McIver, Matthew R.
The sandy barrier islands of Cape Hatteras National Seashore, USA, attract large seasonal influxes of tourists, and are host to numerous motels, rentals and second homes. To investigate the impacts of nearby urbanization on public trust waters, sampling was conducted in nine brackish water bodies within this coastal national park. A large tidal urban ditch delivered runoff-driven fecal-contaminated water directly into public beach waters. At all sites except the control, ammonium, phosphorus and fecal bacteria concentrations were high, strongly seasonal and significantly correlated with community water usage, indicating that increased septic tank usage led to increased pollutant concentrations in area waterways. Nutrients from septic systems caused ecosystem-level problems from algal blooms, BOD, and hypoxia while fecal microbes created potential human health problems. Septic system usage is widespread in sensitive coastal areas with high water tables and sandy soils and alternatives to standard septic systems must be required to protect human health and the environment.
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