Fingerprinting and source apportionment of dioxin contamination of soils and chicken eggs in Southeast and Central Vietnam.

Free-range chicken eggs and topsoil samples from private households in Southeast and South Central Coast of Vietnam were investigated to identify potential PCDD/F sources using Positive Matrix Factorization (PMF) approach. The PMF-extracted egg congener patterns were transformed to soil patterns using bioaccumulation factors and then compared to extracted soil and known dioxin sources patterns described in the literature. Free-range chicken egg PCDD/F profiles allowed to more precisely identify and distinguish potential PCDD/F sources. Five main PCDD/F sources were identified: open burning, vehicle emissions, background atmospheric deposition, Agent Orange, and so-called OCDD dechlorination pattern. The latter is characteristic for natural formation or ultimate weathering under tropical conditions of any primary source with predominant OCDD. Agent Orange source contribution ranged from 48 to 96% in soils, from 9 to 94% in eggs in hotspots, and from 10 to 31% in soil and from 4 to 45% in eggs in sprayed areas, respectively. Contributions of other sources varied significantly between sites.

Novel Extract from Beetle Ulomoides dermestoides: A Study of Composition and Antioxidant Activity.

A biologically active extract from the darkling beetle Ulomoides dermestoides was obtained using the electro-pulse plasma dynamic extraction method. The beetle water extract contained a complex of antioxidant substances such as antioxidant enzymes and nonprotein antioxidants, as well as a complex of heat shock antistress proteins. This determines the rather high antioxidant activity of the aqueous extract of the beetle, i.e., 1 mg of dry matter/mL of the extract has an equivalent antioxidant activity to 0.2 mM Trolox (a water-soluble analog of vitamin E). It was shown that the beetle extract can lead to a 25-30% increase in the average lifespan of nematode Caenorhabditiselegans, under normal conditions, and a 12-17% increase under conditions of oxidative stress (with paraquat), and significantly inhibits the fructosylation reaction of serum albumin. Therefore, the beetle aqueous extract shows promise as a biologically active complex exhibiting antioxidant activity.

PCDD, PCDF, and PCB exposure in current and former firefighters from Eastern Siberia.

The current study examines whether the occupation of firefighting contributes to exposure to polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (PCBs). We compared serum dioxin concentrations and congener profiles of current firefighters (n=13) with those of men who have ceased employment as firefighters (n=17) and with men employed in occupations other than firefighter (n=10). We found that compared to former or non-firefighters, current firefighters have higher levels of dioxins primarily due to the contribution of PCBs and to a lesser extent PCDFs. PCDFs were significantly higher in former firefighters compared to non-firefighters (p<0.05). Comparisons with studies performed by other investigators suggest that local environmental conditions contribute to some of the elevation of PCBs. The congeners 1,2,3,4,6,7,8-heptachlorodibenzodioxin and PCB-114 were significantly higher in current firefighters when compared to former or non-firefighters. Moreover, levels of these congeners were inversely correlated with years since employed as firefighter (Spearman r=-0.610, p=0.009 and Spearman r=-0.53, p=0.03, respectively). The classes of dioxins show an overall decline with years since employed as firefighters, this decline is most evident with PCDDs (Spearman r=-0.46, p=0.06). Together, the combination of evidence supports firefighting as a source of exposure to dioxins.

Contamination of Russian Baltic fish by polychlorinated dibenzo-p-dioxins, dibenzofurans and dioxin-like biphenyls.

Nineteen species of fish products caught and produced in the Russian economic zone of the Baltic region in 2002-2005 were analyzed for polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and dioxin-like biphenyls (WHO-PCBs). Freshwater fish had significantly lower PCDD/PCDFs levels than most saltwater fish, except cod's fillet for which TEQ was comparable. In some cases pollutant levels of sea fish tissues essentially exceeded current regulatory values. Concentration of WHO(PCDD/F)-TEQ ranged from 0.06 to 0.57pg/g f.w. for freshwater fish, and from 0.16 to 17.83pg/g f.w. for sea fish. The special concern is caused by the high concentration of dioxin-like PCBs, whose contribution to the WHO-TEQ(PCDD/F,PCB) considerably exceeded that of PCDDs and PCDFs. Concentration of WHO(PCB)-TEQ ranged from 2.56 to 124.40pg/g f.w. Profiles of PCDD/Fs congeners in fish were rather similar: in our opinion, the most probable sources of pollution were chlorine bleaching and outflow of PCBs. There is no real reason to assume that fish contamination was affected by the fungicide Ky-5 or similar chlorophenols mixtures. Relative contributions of each dioxin-like PCBs congener to total TEQ in fish tissue are presented in Fig. 2. Profiles of dioxin-like PCBs in general are close to Aroclor 1254, though in some cases there are essential differences.