Immunization prevents DDT buildup in mouse tissues.

DDT is used for pest control, causing health and environmental hazards in some parts of the world. The goal of this study was to assess whether immunization against a toxic compound could reduce the toxicant uptake of an organism, specifically to develop a DDT immunization that promotes the production of specific antibodies and assess whether it reduces DDT levels in the bodies of mice that are exposed to DDT by intake. BALB/c mice were immunized with DDT-keyhole limpet hemocyanine (DDT-KLH) conjugate (n=10) or unconjugated KLH (n=10), which was used as a control. After the immunization specific DDT antibodies in the mouse serum were determined by ELISA and then the mice were fed chow containing 40 mg/kg of DDT for 45 days. Finally, the concentration of DDT and its metabolites, DDE and DDD, in various tissues was measured by gas chromatography. Specific DDT antibody levels were significantly higher in the DDT immunized group than in the control group. DDT, DDE and DDD levels in adipose tissue, blood, brain and spleen were significantly reduced in the DDT immunized animals relative to control animals. However, DDT and DDD levels were higher in the liver compared to the control group. The findings indicate that the DDT immunization reduces the total uptake of DDT in animal tissues, which is reflected by the lower levels in adipose tissue, blood, brain and spleen. The elevated levels in liver suggest that DDT-antibody complexes in mouse serum are delivered to the liver.

Temporal trends of organochlorine contamination in Black Guillemots in Iceland from 1976 to 1996.

The levels of several different persistent organochlorines (OCs) in Black Guillemots Cepphus grylle, collected during the summers of 1976-1996 at Breioafjörour in W-Iceland, were investigated. The levels of about 40 different organochlorines (PCBs, DDTs, chlordanes, toxaphenes, HCH, HCB) were compared with respect to age, sex, fat content, and year of collection. The levels of PCBs correlated very closely with those of DDE, indicating long-range transport as the major source of these contaminants in Iceland, with the ratio PCBs/DDE mostly in the range of 2-5. Unlike the Gyrfalcon Falco rusticolus, the organochlorine levels did not seem to accumulate substantially with age, neither in males nor females. The variation in the levels of OCs at the age of 2 years was even greater than the variation in OC levels over an age range of 12 years. In immature birds the levels of PCBs, DDE, HCB and beta-HCH declined very slowly (T(1/2) from 12 to 20 years) over the years 1976-1996, whereas the levels of alpha-HCH and p,p'-DDT declined much faster. The levels of trans-nonachlor, alpha-chlordane, gamma-chlordane, oxychlordane, and toxaphene did not correlate with the year of collection. As the Black Guillemot is mostly a resident seabird, feeding mainly on small fish and invertebrates, this investigation should give a good indication of the temporal trends of organochlorine pollution at Breioafjörour, Iceland, during this 20 year period and is likely to reflect baseline trends in the marine environment of the North-Atlantic Ocean.

Temporal trends of contaminants in cod from Icelandic waters.

Contaminants have been analyzed in cod (Gadus morhua) since 1990 as part of the national monitoring program for the environmental conditions in the sea around Iceland. The aim of this study was to determine the temporal trends of persistent organic pollutants (POPs: polychlorinated biphenyls (PCBs), p,p'-dichlorodiphenyl dichloroethene (p,p'-DDE), hexachlorobenzene (HCB), hexachlorocyclohexanes (HCHs), chlordanes (CHLs) and toxaphenes (Tox)) and trace elements (As, Cd, Cu, Hg, Pb, Se and Zn) in cod over the last two decades at two different locations in the Arctic Ocean north of Iceland. The relationship between the contaminant concentrations and biological covariates was also determined. All of the POPs showed decreasing trends but the trace elements showed no clear signs of trend except arsenic which showed an increasing trend and zinc which showed a decreasing trend. The concentration of the POPs were lower or similar in the Icelandic cod compared to cod sampled in Norway, the Barents Sea and in the Baltic Sea, except for HCB which was higher in the Icelandic cod compared to the Norwegian cod. The concentration of the trace elements As, Cu, Hg and Zn were similar in the Icelandic cod compared to cod sampled in Norway and Greenland but the concentration of Cd was higher in the Icelandic cod. The inclusion of the biological covariates was found to be important for the statistical analysis. The POPs had a positive relationship with liver fat content but negative relationship with liver weight. The trace elements had a negative relationship with liver fat and liver weight except As which had positive relationship with liver weight. Only positive relationships were observed between the contaminant concentrations and length.

Spatial and temporal trends of contaminants in mussel sampled around the Icelandic coastline.

Contaminants have been determined in blue mussels (Mytilus edulis) at 11 locations around the Icelandic coastline from 1990 to 2010. The aim of the present study was to investigate if there has been a change in concentration of contaminants around the Icelandic coastline for the last two decades and if the concentrations and changes, if present, were consistent between locations. Concentrations of the persistent organic pollutants, p,p'-dichlorodiphenyldichloroethene (p,p'-DDE), hexachlorobenzene (HCB), α-hexachlorocyclohexane (α-HCH), polychlorinated biphenyl (PCB-153) and trans-nonachlor, have decreased at most of the sampling locations in Iceland in recent years. However, an increasing trend was found at a few locations that could be explained by anthropogenic activity. The concentration levels of the persistent organics were much lower than found at the Norwegian, USA and Chinese coasts, especially levels of p,p'-DDE. The concentration of copper and selenium had a consistent pattern of change and concentration between locations over the period which showed a decreasing trend in recent years. The trace elements arsenic, cadmium, mercury and zinc showed more variation in concentration between locations, the concentration of arsenic, mercury and zinc was fairly stable over the period, whereas there were fluctuations in cadmium concentrations. The concentrations of cadmium and zinc were observed to be somewhat higher than found in mussels from Norway, USA and China but values of mercury and lead were much lower in the mussel sampled in Iceland. The higher concentrations of cadmium and zinc can be explained by the volcanic activity in Iceland but no major anthropogenic sources of trace elements are known in Iceland.

Persistent organochlorines, sedentary occupation, obesity and human male subfertility.

BACKGROUND: Studies have suggested that the quality of human semen has been declining over recent decades, presumably because of lifestyle or environmental factors. METHODS: Polychlorinated biphenyls and organochlorine pesticides were analysed in the plasma of 25 men with poor semen quality, 20 men with normal semen quality and idiopathic subfertility and 27 men with normal semen quality and female factor subfertility. Samples of seminal fluid were also analysed to assess the relationship between the levels in blood and semen. RESULTS: The results indicate no difference in the levels of organochlorines between the groups. The levels of organochlorines in seminal fluid were proportional to the levels in plasma, but approximately 40 times lower. Men with poor semen quality were three times more likely to be obese than men with normal semen quality. There was also a significant negative correlation between semen quality parameters and body mass index among men with normal semen quality. The prevalence of sedentary work was lowest among men with the best semen quality. CONCLUSIONS: Poor semen quality was found to be associated with sedentary work and obesity but not with plasma levels of persistent organochlorines. More research is needed to assess whether sedentary lifestyle and obesity are causal factors in the decline of semen quality.

[Phytoestrogens and human health.].

Recently there has been a growing interest in phytoestrogens, because they have been proven to play a protective role against many diseases that have been related to lifestyle in the westernized countries. The four main classes of phytoestrogens are: isoflavones, flavones, coumestrans and lignans. Known mechanisms of action include estrogen receptor agonism and possibly antagonism, influences on sex hormone binding globulin and/or key enzymes in sex hormone production and metabolism. Other effects not linked to sex hormones, such as antioxidant activity, antiproliferative activity and inhibition of angiogenesis, have also been suggested. A short review of the most studied health effects that have been linked to phytoestrogens is presented, such as prevention of certain types of cancer, osteoporosis and coronary heart disease.