Organic pollutants in compost and digestate. Part 2. Polychlorinated dibenzo-p-dioxins, and -furans, dioxin-like polychlorinated biphenyls, brominated flame retardants, perfluorinated alkyl substances, pesticides, and other compounds

Compost and digestate are important recycling fertilizers and have beneficial effects on soil parameters. However, they can contain significant amounts of organic pollutants. Here, the first comprehensive data set on dibenzo-p-dioxins and -furans (PCDD/F), dioxin-like polychlorinated biphenyls (DL-PCB), brominated flame retardants, perfluorinated alkyl substances (PFAS), pesticides, phthalates, nonylphenol and chlorinated paraffins (CP) in source-separated compost and digestate from Switzerland is presented (n = 3-18). The median summation 17PCDD/F and summation 12DL-PCB concentrations were at 3.2 ng I-TEQ kg(-1)dry weight (dw) and 3.0 ng WHO-TEQ kg(-1)dw, respectively. Brominated diphenyl ether 209 (BDE 209) accounted for 72% of the total polyBDE content (10 microg kg(-1)dw). Hexabromocyclododecane (HBCD) and tetrabromobisphenol A (TBBPA) levels were at 100 and 0.51 microg kg(-1)dw, respectively. PFAS were identified for the first time in compost and digestate (median concentration 6.3 microg kg(-1)dw, summation 21compounds). Out of 269 pesticides analysed, 30 fungicides, 14 herbicides, eight insecticides and one acaricide were detected. Di-(2-ethylhexyl)phthalate (DEHP) median concentration accounted for 280 microg kg(-1)dw and nonylphenol was below the detection limit of 1 mg kg(-1)dw. The sum of short and medium chain CP was between 90 and 390 microg kg(-1)dw. The concentrations observed were at or above the levels found in background soils, which are the main recipient of compost and digestate. Where actually applied, compost can contribute considerably to the total input of organic pollutants to the soil. However, on a total Swiss agricultural area base, inputs seem to be limited.     

Common frogs response to agrochemicals contamination in coffee plantations,Western Ghats,India

This study highlights the health status of frogs in coffee plantations of Western Ghats. Coffee is one of the major commercial crops in the Western Ghats of India. In these plantations, farmers extensively use agrochemicals including pesticides and synthetic fertilisers. The practice of agrochemical usage can negatively affect non-target organisms like amphibians. The area has reported many amphibian species living in and around plantations. A total of 334 frogs from reference sites (10 abnormal frogs) and a total of 258 frogs (19 abnormal frogs) were collected from contaminated sites. We considered major biomarkers like hepato-somatic index, gonado-somatic index, morphological abnormalities and acetylcholinestarse activities for evaluating the health status of frogs. In our study, the hepato-somatic index and gonado-somatic index were found to be higher in a grochemical contaminated sites. Whereas, acetycholine esterase activity in brain and liver tissues of frogs in contaminated sites were low compared to reference sites. High rate of incidence of morphological abnormality (7.36%), increased hepato-somatic index (14.86%) and gonado-somatic index (male; 8.88% and female; 17.51%) and low acetylcholine esterase activities in brain (41.5%) and liver (46.9%) indicates the lower health status of frogs living in coffee plantations that are regularly treated with agrochemicals.     

Consecutive geoelectric measurements reveal the downward movement of an oxidation zone

An investigation program for monitoring pyrite oxidation on a conveyer bridge dump used geoelectric measurement for monitoring the progress of pyrite oxidation within the dump. The results of the geoelectric measurement show that low soil-pH and high pore water conductivity correlate with low soil resistivity values. The soil resistivity values are dominated by high pore water conductivity. The influence of changes in water saturation on resistivity was comparably low. An increase in pyrite oxidation was observed in areas with high porosity due to low dump density. Consecutive geoelectric measurements revealed locally differentiated downward movement of an oxidation zone caused by dump heterogeneity.     

Pesticide residues in products of plant origin in the European Union

The results of a co-ordinated monitoring programme for pesticide residues in the European Union and Norway carried out in 1996 and 1997 are presented. The aim of this programme is to work towards a system, which makes it possible to estimate actual dietary pesticide intake for the population of the European Union. Based on a statistically dérived sampling plan and within the limited number of pesticides/commodities analysed, the most critical pesticides (benomyl group and dithiocarbamates) and commodities (mandarine and lettuce) were identified. In case of detected non-compliances, repeated sampling and, if necessary, enforcement actions are to be taken by national authorities. The programme will be continued in the next years.