With the continuing shift of industrial activities in developing and transition economies, which often have poor regulation (and weak self-regulation of industries), additional global challenges regarding POPs and other contaminated sites may be expected. In this respect, a comprehensive application of the "polluter pays principle" in these countries will also be a key to facilitate the clean-up of contaminated areas and the prevention of future contaminated sites. The threats and challenges of contaminated sites and the high costs of securing/remediating the problems highlight the need for a comprehensive approach based upon integrated pollution prevention and control. If applied to all polluting (and potentially polluting) industrial sectors around the globe, such an approach will prove to be both the cheapest and most sustainable way to underpin the development of industries in developing and transition economies.

This study investigated the occurrence of polychlorinated biphenyls (PCBs), and several additive brominated flame retardants (BFRs) in indoor dust and air from two Vietnamese informal e-waste recycling sites (EWRSs) and an urban site in order to assess the relevance of these media for human exposure. The levels of polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD), 1,2-bis-(2,4,6-tribromophenoxy)ethane (BTBPE) and decabromodiphenyl ethane (DBDPE) in settled house dust from the EWRSs (130-12,000, 5.4-400, 5.2-620 and 31-1400 ng g(-1), respectively) were significantly higher than in urban house dust but the levels of PCBs (4.8-320 ng g(-1)) were not higher. The levels of PCBs and PBDEs in air at e-waste recycling houses (1000-1800 and 620-720 pg m(-3), respectively), determined using passive sampling, were also higher compared with non-e-waste houses. The composition of BFRs in EWRS samples suggests the influence from high-temperature processes and occurrence of waste materials containing older BFR formulations. Results of daily intake estimation for e-waste recycling workers are in good agreement with the accumulation patterns previously observed in human milk and indicate that dust ingestion contributes a large portion of the PBDE intake (60%-88%), and air inhalation to the low-chlorinated PCB intake (>80% for triCBs) due to their high levels in dust and air, respectively. Further investigation of both indoor dust and air as the exposure media for other e-waste recycling-related contaminants and assessment of health risk associated with exposure to these contaminant mixtures is necessary.

No abstract

Dieldrin and endrin, a group of persistent organic pollutants (POPs), were used extensively on arable land in Japan from 1958 to 1971. Because of their extreme persistence in soils, dieldrin and endrin have been detected in cucumber fruits produced in some areas at concentrations exceeding the limit set by the Food Sanitation Law. Thus, we compared the uptake of dieldrin and endrin by 32 plant species of arable crops in 17 families and by 34 cultivars of Cucurbita sp. grown in contaminated soil to select a candidate cleaning crop for phytoremediation and substitute produce crops. Cucurbits took up more dieldrin and endrin than the other families, and uptake by zucchini was the highest. Apart from the cucurbits, only jute (Tiliaceae) took up any dieldrin and endrin, and uptake by the other 15 families was negligible. Among Cucurbita sp., a number of cultivars took up nearly as much dieldrin and endrin as zucchini, and some took up less than popular rootstock cultivars for graft cultivation of cucumber. These results suggest that cucurbits, especially zucchini, would make good candidates for phytoremediation, and non-cucurbits crops would make good substitute crops in dieldrin-contaminated and endrin-contaminated fields. Moreover, low-uptake Cucurbita sp. cultivars offer promise for breeding substitute rootstocks for grafting cucumber. To determine the uptake mechanism of dieldrin and endrin, a sand culture experiment was conducted. Komatsuna (Brassica campestris var. perviridis), soybean and tomato, which took up negligible chemicals from soil, took up significant quantities from sand culture mixed with dieldrin and endrin. Therefore, even non-cucurbits accumulate dieldrin and endrin under saturated conditions in the rhizospere. This result suggests that cucurbits are able to desorb or dissolve dieldrin and endrin that are strongly sorbed in soil.Dieldrin and endrin uptake by several plants 87

A nationwide monitoring of atmospheric POPs (persistent organic pollutants) was conducted in Ghana between May and July 2010, applying polyurethane foam (PUF) disk passive air samplers (PAS). Reported here are preliminary findings on PCNs, an industrial organic contaminant currently under review for possible listing under the global chemical treaty. The present results constitute the first set of nationwide data on air PCNs from a West African country. Contrary to expectation, air PCNs levels were quite high in Ghana, at an average of 49 ± 5.4 pg/m(3). The coastal (southern) zone of Ghana appeared the most impacted, with crude open burning of waste, industrial emissions, and the harbor environment identified among possible emission factors. Tri- and tetra-CNs (the lowly chlorinated homologues) predominated in the atmosphere, altogether constituting approximately 90% of total PCN homologues composition. Increased volatilization under tropical conditions was presumed a key factor that contributed to this high atmospheric input of lowly chlorinated homologues. We further observed a significant level of fractionation of PCN homologues across the breadth of the country. The percentage composition of the lowly chlorinated homologues increased northwards, probably because of their transportation in the direction of prevailing winds. From congener profile analysis, PCN-45/36 is proposed as a possible source marker for emissions preempted by uncontrolled waste burning activities. Dioxin-like toxicity of air PCNs in Ghana was estimated to range 0.49-5.6 fg TEQ/m(3). This study brought to the fore the emerging problems of nonagricultural organohalogens that covertly might be confronting the environment in African nations like Ghana.

No abstract

The dissipation behavior of water-extractable pesticides in soils is important when assessing the phytoavailability of pesticides in soils. This process is less understood than pesticide extraction with organic solvents. To elucidate the dissipation behavior of water-extractable pesticides in soils, we conducted an incubation study using 27 pesticides and five Japanese soils. The rate of decrease of the level of pesticides in water extracts was faster in soils than that of total extracts (water extracts and acetone extracts). This suggests that time-dependent sorption contributed to the difference in the dissipation between the pesticides in water and total extracts from soils. Increased apparent sorption coefficients (Kd,app) with time were positively and significantly correlated with Kd,app values of a 0 day incubation [Kd,app(t0)]. This empirical relationship suggests that Kd,app(t0) values can predict the time-dependent increase in Kd,app and the dissipation of water-extractable pesticides in soils.

We examined the effect of Cucurbita sp. rootstock on dieldrin concentration in grafted cucumber (Cucumis sativus L.) fruits grown in two types of contaminated soils by pot experiment. The two soils consisted of an Andosol and a Brown Lowland soil and contained 319 and 89 mg dieldrin/kg on a dry weight basis, respectively. Dieldrin concentration in cucumber fruits grafted on low-uptake rootstock (ca. 14-40 mg/kg on a fresh weight basis) decreased by 50-70% compared with those grafted on high-uptake rootstock, for each case of two scion cultivars used. Dieldrin concentration in grafted cucumber fruits basically depended on the content in the aerial part, and not on the dieldrin distribution or the water content in the fruits. Selecting low-uptake rootstock is a promising practical technique to reduce dieldrin concentration in cucumber fruits grown in contaminated fields.