Determination of polybrominated diphenyl ethers in soil and sediment from an electronic waste recycling facility

In this study samples of ten species of fish were analyzed for concentrations of organochlorine pesticides, PCBs and heavy metals (Pb, Cd, and Cu). Fish were captured using electric fishing on ten sites along the Dr?me river (Rh?ne-Alpes region). Quantitative determination of the organochlorine and PCBs compounds was performed by gas chromatography-electron-capture detection (GC-ECD). The concentrations of heavy metals were determined by atomic absorption spectrophotometry. Samples contained detectable concentrations of lindane, PCBs, and heavy metals but at concentrations below the maximum residue limit (MRL). Non-parametric statistical analysis was performed to distinguish groups of sites with different levels of contamination. PCBs concentrations increased along the river with four groups of sites significantly different from each other. Cadmium concentrations were below the MRL. Lead contamination showed two groups significantly different and a repartition similar to PCBs. Copper contamination was correlated with the localization of vineyards. We assessed the potential effects of contamination the otter (Lutra lutra). The concentrations of all pollutants analyzed in fish sampled in this study are lower than the threshold values described in literature. The Dr?me river is relatively unpolluted river, and the establishment of otter populations should not be affected by pollution.     

Inconsistency and comprehensiveness of risk assessments for heavy metals in urban surface sediments

Numerous indices have been developed to assess environmental risk of heavy metals in surface sediments, including the total content based geoaccumulation index (I_geo), exchangeable fraction based risk assessment code (RAC), and biological toxicity test based sediment quality guidelines (SQGs). In this study, the three indices were applied to freshwater surface sediments from 10 sections along an urbanization gradient of the Grand Canal, China to assess the environmental risks of heavy metals (Cu, Pb, Zn, Cd, and Cr) and to understand discrepancies of risk assessment indices and urbanization effects regarding heavy metal contamination. Results showed that Cd, Zn, and Pb were the most enriched metals in urban sections assessed by I_geo and over 95% of the samples exceeded the Zn and Pb thresholds of the effect range low (ERL) of SQGs. According to RAC, Cu, Zn, Cd, and Cr had high risks of adversely affecting the water quality of the Grand Canal due to their remarkable portions of exchangeable fraction in surface sediment. However, Pb showed a relative low risk, and was largely bounded to Fe/Mn oxides in the urban surface sediments. Obviously, the three assessment indices were not consistent with each other in terms of predicting environmental risks attributed to heavy metals in the freshwater surface sediments of this study. It is recommended that risk assessment by SQGs should be revised according to availability and site specificity. However, the combination of the three indices gave us a comprehensive understanding of heavy metal risks in the urban surface sediments of the Grand Canal.     

Residual levels of DDTs and PAHs in freshwater and marine fish from Hong Kong markets and their health risk assessment

Axial and ventral muscle from 10 each species of freshwater and marine fish purchased from markets in Hong Kong were analyzed for dichlorodiphenyltrichloroethane (total DDTs including DDE, DDD and DDT) and polycyclic aromatic hydrocarbons (PAHs). Among the 10 freshwater fish species, rice field eel (Monopterus albus) showed significantly higher levels of DDTs in both ventral (125 ng/g wet wt) and axial muscle (127 ng/g wet wt) than the other species. The highest concentration of PAHs was detected in catfish (Clarias fuscus), with 24.8 ng/g in ventral muscle and 9.1 ng/g in axial muscle. As to marine fish, snubnose pompano (Trachinotus blochii) showed significantly higher levels of DDT and its metabolites (1018 ng/g in ventral and 409 ng/g wet wt in axial tissues) than all other marine fish species. The overall concentrations of PAHs in marine fish species were 15.5-57.0 ng/g (axial muscle) and 18.1-118 ng/g wet wt (ventral muscle) where yellow seafin (Acanthopeyrus latus) and golden threadfin bream (Nemipterus virgatus) exhibited the highest concentrations of PAHs in the axial and ventral muscles, respectively. In general, results showed that levels of PAHs in Hong Kong market fish was low and do not expect to cause any concern for human consumption. However, the levels of DDTs in fish samples ranged from 1.10 to 1018 ng/g wet wt, and based on a fish consumption rate of 142.2g/day to calculate the screening value of 14.4 ng/g wet wt for human consumption (USEPA, 2000. Guidance for assessing chemical contaminant, data for use in fish advisories, vol. 1: fish sampling and analysis, third ed. EPA 823-R-95-007. Office of Water, Washington, DC), there were 9 out of 20 (45%) muscle samples of freshwater fish species and 14 out of 20 (70%) muscle samples of marine fish species had elevated levels of DDTs exceeded the screening value. It was also suggested to use ventral muscle for detecting concentrations of persistent organic pollutants in fish.     

Biota–sediment accumulation factor (BSAF), bioaccumulation factor (BAF), and contaminant levels in prey fish to indicate the extent of PAHs and OCPs contamination in eggs of waterbirds

Samples of pond sediment, fish, and shrimp were collected from the Ramsar site at Mai Po marshes, Hong Kong (south China), and samples of pond sediment, fish, and shrimp, as well as eggs of water birds (Chinese Pond Herons (Ardeola bacchus) and Little Egrets (Egretta garzetta)), were collected from two smaller wetland sites at Jiangsu Province (mid-China), between 2004 and 2007. Accumulation levels of polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs) in the biota were used to calculate biota–sediment accumulation factor (BSAF) and bioaccumulation factor (BAF). For fish and shrimp, BSAFs of OCPs (3.8–56) were greater than those of PAHs (0.12–6.3). BSAFs and BAFs of 11–79 and 4–34, respectively, were registered for OCPs in eggs of the birds and were greater than those for PAHs (0.11–1.5 and 0.02–1.3, respectively). Assuming that fish were the main prey of the birds, greater bioaccumulation of OCPs was detected for both bird species (BAFs?=?4.5–34), while accumulation of PAHs was only detected in Little Egret (BAF?=?1.3). A significant linear relationship (p?<?0.01) was observed between concentrations of OCPs in bird eggs and in the prey fish. The present study provides a new possibility of using OCP levels detected in prey fish to predict the extent of OCPs contamination in eggs of waterbirds including the endangered species, as a noninvasive method.     

PESTICIDE ACCUMULATION IN A NEW IMPOUNDMENT IN IOWA1

ABSTRACT: Estimates were made of the amounts of selected pesticides entering and leaving Saylorville Reservoir, a new partly filled impoundment on the Des Moines River. Samples were collected at 1– or 2-week intervals at stations above, in, and below the reservoir. Atrazine, alachlor, and cyanazine were found only in the dissolved state, and dieldrin and p, p′ -DDE in both the, dissolved and suspended state. Heptachlor epoxide, p,p-DDT. p, p′ -DDD, 2,4-D, 2,4,5-TP, endrin, lindane, methoxychlor, propachlor, and toxaphene were not detected or were at very low concentrations. Estimated deposition in the reservoir from September 1977 to October 1978 was 281 kg atrazine, 251 kg alachlor, 26 kg cyanazine, 16 kg dieldrin, and 20 kg p, p′ -DDE.     

Developing a Monitoring Protocol for Visitor-Created Informal Trails in Yosemite National Park,USA

Informal trails created or perpetuated by visitors is a management challenge in many protected natural areas such as Yosemite National Park. This is a significant issue as informal trail networks penetrate and proliferate into protected landscapes and habitats, threatening ecological integrity, aesthetics, and visitor experiences. In order to develop effective strategies for addressing this problem under an adaptive management framework, indicators must be developed and monitoring protocol must be established to gather timely and relevant data about the condition, extent, and distribution of these undesired trail segments. This article illustrates a process of developing and evaluating informal trail indicators for meadows in Yosemite Valley. Indicator measures developed in past research were reviewed to identify their appropriateness for the current application. Information gaps in existing indicator measures were addressed by creating two new indices to quantify the degree of informal trailing based on its land fragmentation effects. The selected indicator measures were applied to monitoring data collected between 2006 and 2008. The selected measures and indices were evaluated for their ability to characterize informal trail impacts at site and landscape scales. Results demonstrate the utility of indicator measures in capturing different characteristics of the informal trail problem, though several metrics are strongly related to each other. The two fragmentation indices were able to depict fragmentation without being too sensitive to changes in one constituent parameter. This study points to the need for a multiparameter approach to informal trail monitoring and integration with other monitoring data. Implications for monitoring programs and research are discussed.     

A new joint publication

Special FeatureWaste Management Research in Korea

A new joint publication