Levels and bioaccumulation of organochlorine pesticides (OCPs) and polybrominated diphenyl ethers (PBDEs) in fishes from the Pearl River estuary and Daya Bay, South China

Fifty fish samples were collected from the Pearl River estuary (PRE) and Daya Bay, South China and were analyzed for DDTs, HCHs, chlordanes and polybrominated biphenyl ethers (PBDEs). Except the high concentrations of DDT observed in fishes, the concentrations of HCHs, chlordanes and PBDEs were low when compared to other regions. BDE-47 was the predominant PBDE congener and the BDE-209 concentrations were relatively low, despite its high concentration in surface sediments. The absence of significant increase of DDT, HCH, chlordane and PBDE concentrations towards higher delta15N values, as well as the lack of a significant correlation (p<0.1) between log concentrations (lipid normalized) and delta15N, may indicate a weak biomagnification of these chemicals in the food webs. Good agreement was observed between their concentrations and lipid contents of the organisms. Bioconcentration was suggested to be responsible for the accumulation of OCPs and PBDEs in the lower trophic organisms in the studied subtropical waters.     

Respiratory health of road-side vendors in a large industrialized city

GOAL, SCOPE AND BACKGROUND: The literature reports a high prevalence of respiratory symptoms associated with exposure to motor vehicle exhaust emissions and people exposed to vehicle emissions are at risk of reduced lung function and cardiovascular performance. Although the effect of traffic emissions is a known risk to respiratory health, retailers are often situated along major roads in a busy urban environment to maximise customers. Shop assistants in an air-conditioned environment should be less exposed to traffic fumes and their lung function should be better preserved compared to 'unprotected' vendors exposed directly to vehicle emissions. The lung function of these two groups of workers has not previously been compared. The aims of this study are to determine if there is a difference in the concentration of respirable particles of diameter less than 10 micrometers (PM10) inside and outside air-conditioned shops along a busy major road; and to compare the lung function parameters, blood lead levels and respiratory symptoms between road-side vendors directly 'exposed' to traffic fumes and vendors working in 'protected' air-conditioned shops along the same road. METHODS: Roadside vendors (n=33) and adjacent shop assistants (n=31) were recruited for the study in a district known to have high emissions and pollution measures. All subjects were asked to complete a questionnaire providing the frequency of their respiratory symptoms. Spirometry pulmonary function tests were conducted and exhaled carbon monoxide levels (ECO), oxygen saturation and blood lead levels (BLL) were measured. PM10 level was concurrently measured in the subject's working environment. Pulmonary function data and ECO levels collected from a cohort of university staff aged > or = 30 years (n=92) at a university campus were included for comparison. RESULTS: The concentration of particulate matter (PM10) at the roadside (210 +/- 70 microg/m3) was significantly higher than inside the shops (130 +/- 40 microg/m3). There was no difference in lung function parameters or BLL between the groups, however the forced vital capacity of both groups of vendors was significantly lower than a 'control' cohort of academic institution personnel (n=92). DISCUSSION: This study illustrated that while the level of pollution improved with air conditioning, this may not be sufficient to prevent respiratory consequences. Our data suggests that a reduction in occupational exposure is not enough to protect these workers. CONCLUSIONS: Air-conditioned work environment is insufficient to protect the respiratory system against the adverse effects of exposure to vehicle emissions. RECOMMENDATIONS: The overwhelming effect of exposure during travel to and from work and at home cannot be underestimated. More stringent guidelines to control pollution appear necessary to protect the respiratory health of both shop-keepers and road-side vendors and further studies to explore the effect on respiratory health of the exposure to pollutants associated with commuting to and from work are warranted.     

Removal of phosphate from water by a highly selective La(III)-chelex resin

A new polymer ligand exchanger (PLE) has been developed for the removal of phosphate in wastewater. This PLE, consisting of lanthanum(III) bound to chelex-100 resin, was prepared by passing LaCl3 solution through a column of chelex-100. Uptake of phosphate from water by this La-chelex resin was investigated in the column mode. The La-chelex resin was able to remove phosphate efficiently from water, and the uptake of phosphate was not affected by the presence of large amounts of anions (0.1M) such as chloride and sulfate. The La-chelex resin was also able to efficiently remove phosphate from seawater to <0.1mg-Pl(-1), and regenerated for reuse by removing the sorbed phosphate by eluting with 6M HCl.     

Assessment of polybrominated diphenyl ethers in eggs of waterbirds from South China

Concentrations of total polybrominated diphenyl ethers (PBDEs) in Ardeid eggs from Hong Kong, Xiamen and Quanzhou in south China ranged from 140-1000, 30-550 and 140-380ngg(-1), lipid wt., respectively. There were spatial and interspecies variations in the abundance and congeneric profiles of PBDEs. The different congeneric profiles observed among the study sites may be associated with the developmental phases of the cities, as well as a possible consequence of debromination of BDE209. Marked concentrations of higher-brominated diphenyl ethers (BDEs 183, 196, 197, 206, 207 and 209) were detected in the egg samples from all sites, probably indicating uptake of BDE209 by top predators, and that there is widespread occurrence of BDE209 in south China. Comparisons of egg concentrations of BDEs 47, 99, 153 and 209 with tentative critical concentrations for neurobehavioral effects and oxidative stress indicated some potential risks for BDE99 and BDE209 in the Ardeid populations.     

Use of protein phosphatase inhibition assay to detect microcystins in Donghu Lake and a fish pond in China

Seasonal variations in the level of total microcystins in water samples collected from Donghu Lake and a fish pond in Wuhan, China, were studied between March 1995 and February 1996 using a protein phosphatase inhibition assay involving a radioactive 32P-labelled substrate. The assay is highly reliable and repeatable, and is probably the most sensitive assay for microcystin detection to date. Results of the survey indicated the presence of microcystins in the water samples, and the concentration of microcystins appeared to be related to the degree of eutrophication and water temperature. There is also a correlative relationship between the quantity of microcystins and the abundance of microcystin-producing cyanobacteria (Anabaena and Oscillatoria) in the water bodies over a year cycle. In the present study, the positive detection of microcystins in water bodies having no signs of algal bloom warns of considerable potential threat of these waters to public health.     

Whole-mount in situ TUNEL method revealed ectopic pattern of apoptosis in cadmium treated naupliar larvae of barnacle (Balanus amphitrite Darwin)

The effect of cadmium on stage II naupliar larvae of barnacle (Balanus amphitrite Darwin) was investigated. Barnacle larvae were exposed to 0-15 microM CdCl(2) for 24 h. Apoptotic cells were stained by the terminal deoxyribonucleotidyl transferase mediated dUTP nick end labelling (TUNEL) method. Incidence of apoptosis, as measured by numbers of animals with ectopic pattern of apoptosis as well as numbers of apoptotic cells per animal, was assessed using confocal microscopy. An increase in incidence of apoptosis was observed in the experimental animals with an increase in cadmium concentration. Mortality increased, and motility decreased, when barnacle larvae were exposed to an increasing concentration of cadmium. The relationship between the occurrence of apoptosis and swimming behaviour was investigated in larvae exposed to 10 microM CdCl(2). Significant increases in apoptosis were detected in the non-motile and dead nauplii. This study suggested that whole-mount in situ TUNEL method may be used to study increased occurrence of apoptotic cells in crustacean larvae.     

战略环境评价(SEA)及其研究进展

战略环境评价(SEA)是目前环境评价领域中令人关注的前沿课题 .本文对 SEA的提出和发展进行了回顾 ,对国外开展SEA的实践进行了归纳分析 ,探讨了 SEA的作用、区域特征、评价因素、基本程序、技术方法和机制 ,论述了 SEA与项目 EIA的关系 ,并介绍了香港和内地 SEA的初步实践 .     

A comparison of mussels (Perna viridis) and semi-permeable membrane devices (SPMDs) for monitoring chlorinated trace organic contaminants in Hong Kong coastal waters

A comparison of mussels (Perna viridis) and semi-permeable membrane devices (SPMDs) was carried out at five sites, representing a gradient of contaminant concentrations, in Hong Kong coastal waters. Mussels, originally collected from a “clean” location, were deployed along with SPMDs at each site for 30 days. Analyses for chlorinated pesticides and polychlorinated biphenyls (PCBs) indicated that SPMDs have potential as monitoring tools, and to some extent can overcome the problems associated with mussels, such as natural variability, differing age, sex, and physical condition. However, in most cases, SPMDs failed to rank the sites in the same order as mussels in terms of contaminant concentrations. Nonetheless, in localities where mussels cannot survive – as shown at Kwun Tong in the present experiment – SPMDs may be valuable in providing an indication of potentially bio-available lipophilic pollutants.