Residues and potential health risks of DDTs and HCHs in commercial seafoods from two coastal cities near Yangtze River Estuary.

Five species of commercial seafoods collected from the local markets in two coastal cities near Yangtze River Estuary (Ningbo and Zhoushan) in 2010 were analyzed to study the residues, potential sources, and health risks of dichlorodiphenyltrichloroethanes (DDTs) and hexachlorocyclohexanes (HCHs) in these areas. The total levels of DDTs and HCHs in the samples ranged from 1.13-20.2 ng g(-1) and 1.23-3.05 ng g(-1) wet weight, respectively, and were at a middle level compared with those from other marine systems. Results from one-way analysis of variance (ANOVA) indicated species-specific distributions of DDTs and HCHs in the seafoods of the studied area, which may be related to their different lipid contents and ecological characteristics. Compositional analysis suggested that historical usage dominates in this area, and fresh inputs of lindane and dicofol may also have part contributions. With respect to DDTs, it can be metabolized into both DDD and DDE simultaneously in seafoods tested. Assessment based on maximum residue levels, acceptable or tolerable daily intakes, and hazard ratios for non-carcinogens suggested no obvious adverse health effects, while the lifetime cancer risks may be increased from dietary exposure to DDTs and HCHs.

Residues and enantiomeric profiling of organochlorine pesticides in sediments from Xinghua Bay, southern East China Sea.

The spatial distribution and chiral signatures of organochlorine pesticides (OCPs) in the surface sediments of Xinghua Bay, southern East China Sea, were investigated. The total OCP concentrations ranged from 9.15 to 40.5 ng/g dry weight, with a predominance of hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethanes (DDTs). The isomer ratios of α-HCH/γ-HCH (less than 1.0) and the predominant ß-HCH implied that HCH residues were derived not only from historical technical HCH use but also from the additional use of lindane in this area. The isomer ratios of p,p'-DDT/(p,p'-DDD + p,p'-DDE) and o,p'-DDT/p,p''-DDT, and a strong correlation (R = 0.83, P < 0.001) between p,p'-DDE and o,p'-DDT depicted a cocktail input pattern of dicofol-type DDT and technical DDT. Moreover, the fact that only cis-chlordane was detectable for all sampling stations suggested the past application of technical chlordane. Based on the sediment quality guidelines (SQG), γ-HCH is the main OCP species of ecotoxicological concern in Xinghua Bay. Enantiomeric analysis showed that the (+)-enantiomers of α-HCH and o,p'-DDT were more prevalent than the (-)-enantiomers in most samples, whereas both racemic and nonracemic residues existed for o,p'-DDD. These results implied that the SQG of chiral OCPs should be reassessed using concentrations of their individual enantiomers.

Residues and chiral signatures of organochlorine pesticides in sediments from Xiangshan Bay, East China Sea.

Residual levels and enantiomeric signatures of hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethanes (DDTs) in surface sediments from Xiangshan Bay, East China Sea were investigated. The concentrations of ∑HCHs (sums of α-, ß-, γ-, and δ-HCH) and ∑DDTs (sums of p, p'-DDT, p, p'-DDD,p, p'-DDE, o, p'-DDT, and o, p'-DDD) ranged from 0.14 to 0.67 ng g⁻¹ and 0.61 to 22.38 ng g⁻¹, respectively. A slight potential health risk to the organism was then indicated for the residual levels of DDTs according to the ERL/ERM guidelines. Moreover, the predominant ß-HCH implied that the technical HCH contamination was mainly due to the historical usage. But the high ratio of DDT/∑DDTs depicted a cocktail input pattern of fresh and weathered DDTs. The enantiomeric fractions (EFs) of α-HCH, o, p'-DDT, and o, p'-DDD were also determined. The degradation of α-HCH was enantioselective in all sediments samples, resulting in an enrichment of (-)-enantiomers. However, the racemic residues of o, p'-DDT and o, p'-DDD were observed in all sediments samples.

Simultaneous detection of antibodies to six nonhuman-primate viruses by multiplex microbead immunoassay.

To maintain healthy nonhuman primates for use in biomedical research, animals are routinely screened for several infectious agents at most facilities. Commonly, monkey serum samples are tested by conventional immunoassays, such as enzyme-linked immunosorbent assays (ELISAs) or Western blotting, for antibodies to specific infectious agents. For testing for antibodies against multiple agents in each sample, conventional immunoassays are laborious and time-consuming. More efficient immunoassays are needed. Accordingly, we have developed a novel multiplex serodiagnostic system based on individually identifiable, fluorescent microbead sets, where each bead set is coated with antigens from a purified preparation of a specific virus. The coated bead sets are mixed to enable the detection of antibodies to multiple viruses in one serum or plasma sample. These viruses include four agents that are routinely tested for maintenance of specific-pathogen-free monkeys, namely, simian immunodeficiency virus, simian type D retrovirus, simian T-cell lymphotropic virus, and herpes B virus, as well as simian foamy virus and rhesus cytomegalovirus, both of which are commonly found in nonhuman primates. This multiplex microbead immunoassay (MMIA) enabled the simultaneous detection of antibodies to all six viruses in single serum samples as small as 1 microliter. The results obtained by MMIA analysis correlated with results of conventional ELISAs, which detect antibodies to single agents. Thus, this multiplex microbead detection system is an efficient diagnostic modality for serosurveillance of nonhuman primates.