Characterization of environmental water samples using strontium and lead stable isotope compositions

A simple procedure using both cation and anion exchange chromatography has been applied in the study of lead and strontium isotope composition in rain and stream water samples from remote catchments in Scotland. Whereas the soil released strontium to stream waters, lead was removed from rain water and the concentrations in stream waters were very low. Highly precise analysis by thermal ionisation mass spectrometry proved necessary in the determination of strontium isotope composition. The ⁸⁷Sr/⁸⁶Sr ratio in rain water was close to that of marine strontium but the ratios in stream waters were constant and highly characteristic for the stream. In the case of the stream at the Sourhope site, the ratio (0.70798 ± 0.00005) was less than that in rain water and probably resulted from the weathering of one specific mineral. The results suggested that the ⁸⁷Sr/⁸⁶Sr ratios could be used as a stable isotope tracer of waters and to provide information on the weathering processes. Two major anthropogenic components of lead were identified in water samples. One had its origin in petrol additives whereas the other was probably of industrial origin. The low ²⁰⁶Pb/²⁰⁷Pb ratios observed in stream waters confirmed the lead as being of anthropogenic origin and the data suggested that there was a movement, albeit very small, of lead from the soil to waters.     

Spatial pattern of arsenic and lead distributions in Jamaican soils

The spatial patterns of arsenic and lead distribution in Jamaican soils were studied using the Geographical Resources Analysis Support System (GRASS) and data from an island wide soil survey. Arsenic and lead were analysed by instrumental neutron activation analysis (INAA) and energy-dispersive X-ray fluorescence (EDXRF) techniques. The frequency distribution of each element is discussed in relation to major lithological groups. The As-Pb background levels for different areas in Jamaica were estimated.     

Current uses of the EPA lead model to assess health risk and action levels for soil

The EPA lead model predicts mean blood lead levels and risk of elevated blood lead levels in children based on lead uptake from multiple sources. In the latest model versions, environmental data from individual homes within a community can be used to predict the overall blood lead distribution and percent risk of exceeding a specific blood lead level (i.e. 10 g dl^–1). Recent criteria used by the EPA to evaluate this information include no more than 5% of houses with a greater than 5% lead risk, and a community weighted-average risk below 5%. Environmental (primarily soil) and blood lead data from a residential community near a smelter were used to illustrate recent uses of the model. Scheduled remediation in the community will remove soil for approximately 60% of the houses (i.e. those with lead levels > 1000 mg kg^–1). After remediation, the model results indicate a relatively low community risk (0.5–1.9%), although the percentage of houses with lead risks above 5% ranged from 3 to as high as 13%, depending on the variation in blood lead and assuming the model's 7 g dl^–1 increase in blood lead with each 1000 mg kg^–1 increase in soil lead level. A comparison of the limited blood lead data with soil lead levels below 1000 mg kg^–1, however, indicated no apparent relationship. Given these uncertainties, less invasive actions than additional soil removal (e.g. exposure intervention, monitoring conditions, and follow-up as necessary) may be appropriate under the new EPA guidance for lead in soil.     

Copper, Lead and Zinc Mobility and Bioavailability in a River Sediment Contaminated with Paint Stripping Residue

A river embankment sediment beneath a road bridge in South Australia had been surveyed on a previous occasion to a depth of 10 cm and found to contain high levels of copper, lead and zinc deposited during previous lead and zinc-based primer paint stripping operations prior to repainting the bridge. Since the river embankment is geologically different from the surrounding non-embankment soils, and a sufficient distance from the bridge along the river embankment could not be traversed, the geological background Cu, Pb and Zn fraction was established initially using a solid phase sequential extraction (SPSE) procedure. Assessment of the degree of contamination and extent of vertical mobility was then established. Copper was a minor contaminant and present predominantly as the geological background species. Lead was partitioned evenly between the oxalate soluble fraction and residual fraction to a depth of 30 cm with a decrease in total Pb concentration from 497 to 141 mg Pb kg^–1 while Zn was predominantly in the oxalate soluble fraction to a depth of 15cm with a decrease in concentration from 1013 to 150 mg Zn kg^–1. The reduced rate of nitrification and the lower total concentration of NO₃ ^–-N together with the higher respiratory quotient, combined with the lower microbial quotient, are indicative of microbial stress due to heavy metal toxicity. In the case of Pb and Zn paint stripping residues, these changes in indicators of microbial health are possibly the result of the greater abundance and hence possible bioavailabilty of organo- and chloro-Pb compared to organo- and chloro-Zn complexes.     

上海粮田锌和铅的生物地球化学

本文介绍了1990—1991年对上海粮田锌和铅的生物地球化学研究.阐述了锌和铅在上述地区的富集和迁移规律.研究了结累锌和铅的地球化学栅栏以及谷物对锌和铅的吸收与富集.     

Reaction of spruce cells toward heavy metals and the influence of culture conditions

BACKGROUND: Plant cell cultures may serve as biosensors for the detection of heavy metals and other toxic substances. Standard culture media and protocols are frequently utilised, but in these media no care is usually taken to control the influence of hormones and nutrients on the reaction of the enzymes or m under consideration as parts of the sensor. The present paper investigates the influence of media composition on the reaction of spruce cells towards heavy metals. METHODS: Spruce cell cultures were grown in a standard medium, either i) alone, ii) containing 0.3% sucrose or iii) containing 3% sucrose and the hormones BAP and NAA. The cell cultures were then incubated in medium with fungal elicitor, H2O2, CdSO4 (50 to 500 microM), or, alternatively, with a standard heavy metal mixture containing 80 microM Na2HAsO4, 150 microM CdSO4 and 200 microM PbCl2. RESULTS: Depending on the nutrient status and hormone availability, large differences in glutathione contents and the GSH/GSSG ratio were observed. However, the cellular redox state seemed to remain more or less constant. Glutathione S-transferase activity was determined with four substrates, and high induction rates for the conjugation of three substrates were observed when hormones were omitted from the media. 1,2-epoxy-nitrophenoxy-propane conjugation was highest in starving cell in the presence of hormones, showing a transient GST induction, with highest rates occurring after 16 hrs following incubation; the induction effect was lost after 24 hrs. CONCLUSION: A medium containing 3% sucrose and both hormones (BAP and NAA) appears to be most favourable for cellular growth as well as the expression of a basis level of detoxification enzymes and antioxidants. With this combination, early responses towards heavy metals at low concentration can be monitored. RECOMMENDATIONS AND PERSPECTIVE: Plant cell cultures are valuable tools for the bioindication of heavy metals and toxic xenobiotics. If standard media and protocols are utilised, the influence of hormones and nutrients on the reaction of the biosensor have to be evaluated thoroughly.     

含莠去津和乙草胺河水灌溉对苗期水稻危害的研究

本文以１９８８、１９９２和１９９３年洋河流域张家口市部分水稻田污染受害事故为背景，通过事故现场调查资料分析、洋河水质监测、宣化区污染源调查、水稻的药害暴露实验和模型计算，研究了含有除草剂莠去津和乙草胺的河水灌溉对苗期水稻的危害。结果显示，河水中莠去津和乙草胺对水稻苗期的安全灌溉浓度分别为０．０１ｍｇ／Ｌ和０．０５ｍｇ／Ｌ；河水中莠去津对水稻的致死浓度是０．１ｍｇ／Ｌ；ｐＨ、ＮＨ３－Ｎ和表面活性剂对这种危害作用具有一定的协同效应；为了满足河水对水稻的灌溉水质要求，污染源允许排放的莠去津和乙草胺分别为１．０ｋｇ／ｄ和２．０ｋｇ／ｄ。     

Nonylphenols in freshwaters of the hydrologic system of an Italian district: association with human activities and evaluation of human exposure

A sampling campaign for the determination of concentrations of nonylphenol isomers (NPs) in freshwaters and sediments of the hydrologic system of the Rieti district (central Italy) was conducted from 2002 to 2003. Eighteen sampling points, selected on the basis of the different human activities in the vicinity, were monitored; six series of water samples (from June 2002 to February 2003) and one of sediment samples (summer 2002) were analyzed by GC/MS.

There was a direct relationship between concentrations of NPs and the presence of urban or industrial activities near the sampling point. However, concentrations of NPs in water were in the range of <0.1–1.4 μg l⁻¹, and their presence limited to short distances from the sources of contamination. Accumulation factors in sediment samples ranged from 10² to 5 × 10³.     

Regional monitoring of lead and cadmium contamination in a tropical grazing land site,Thailand

An investigation was carried out to monitor Pb and Cd contamination in grazing land located near a highway. Environmental media at different distances fromhighway (soil, grass, water, cow's forage, fertilizer,manure and milk samples) were collected from three samplinglocations. Soil and grass were characterized by high metalmobility (soil with Pb: 5.25±0.71–14.59±1.17 mgkg^-1, dry mass and Cd: 0.038–0.33±0.04 mg kg^-1, dry mass and grass with Pb: 0.76±0.05–6.62±0.18 mg kg^-1, dry mass and Cd: 0.17±0.01–0.73±0.09 mg kg^-1, dry mass). One-way analysis of variane (ANOVA) was applied to find out the correlation between metal (total and bioavailable) concentrationsin the soil and the distance from roadside. In most cases, the finding showed that plants growing nearer to the highway are usually exposed to more heavy metal accumulations than those awayfrom the highway. In addition, a correlation was established between plant available metal concentrations and plant metaluptake concentrations.Analysis of fertilizer and manure showed considerable amountof metals (fertilizer with Pb: 1.53±0.06 mg kg^-1 andCd: 0.038 mg kg^-1 and manure with Pb: 2.55–3.34 mgkg^-1 and Cd: 0.14–0.31 mg kg^-1). Long termsimultaneous application of fertilizer and manure on thecommercial farm showed higher metal accumulation in the soiland plants than those of co-operative farm Considerableconcentrations of metals (Pb: 1.60–2.94 mg kg^-1 andCd: 0.025–0.19 mg kg^-1) were observed in fodder. The finding clearly demonstrated that there are seasonalvariation in total daily metal intake by individual cow (Pb:109.37 mg day^-1 (dry), 273.47 mg day^-1 (rainy) andCd: 2.02 mg day^-1 (dry), 19.62 mg day^-1 (rainy)).The provisional tolerable weekly intake of heavy metals incows is 390 g Pb and 28 g Cd per kg bodyweight in the rainy season and 156 g Pb and 2 gCd per kg body weight in the dry season. The levels of metals (Pb: 0.014 mg L^-1 and Cd: not detectable) and bio-transferfactor (10^-5–10^-4) in raw milk were found to be well below the Codex Alimentarius Commissions Draft (1997). Ouranalysis revealed that improvements on farm management give significant reduction in elevated levels of Pb and Cdin soil and plants, and however leads to minimize the amountof Pb and Cd in consumed milk.     

环境中抗生素残留潜在风险及其研究进展

抗生素是一类目前在各国广泛应用的药物,主要通过粪便散布于环境中。在一些国家的河流和湖泊已经检测到了不同种类的抗生素,其在环境中的残留引起了研究者的关注。文章就抗生素的生产和使用、环境中抗生素的暴露途径以及其生态影响进行了综合归纳,并对目前国内外的研究进展进行了分析和讨论,提出了今后的研究重点和方向。