Interaction Between Persistent Organic Pollutants and C-reactive Protein in Estimating Insulin Resistance Among Non-diabetic Adults / 예방의학회지

OBJECTIVES: Chronic inflammation is now thought to play a key pathogenetic role in the associations of obesity with insulin resistance and diabetes. Based on our recent findings on persistent organic pollutants (POPs) including the lack of an association between obesity and either insulin resistance or diabetes prevalence among subjects with very low concentrations of POPs, we hypothesized that POP concentrations may be associated with inflammation and modify the associations between inflammation and insulin resistance in non-diabetic subjects. METHODS: Cross-sectional associations among serum POPs, C-reactive protein (CRP), and homeostasis model assessment of insulin resistance (HOMA-IR) were investigated in 748 non-diabetic participants aged > or =20 years. Nineteen types of POPs in 5 subclasses were selected because the POPs were detectable in > or =60% of the participants. RESULTS: Among the five subclasses of POPs, only organochlorine (OC) pesticides showed positive associations with CRP concentrations, while polychlorinated biphenyls (PCBs) showed inverse associations with CRP concentrations. There were statistically significant interactions between CRP and OC pesticides and between CRP and PCBs, in estimating HOMA-IR (P for interaction <0.01 and <0.01, respectively). CRP was not associated with HOMA-IR among subjects with low concentrations of OC pesticides or PCBs, while CRP was strongly associated with HOMA-IR among subjects with high concentrations of these POPs. CONCLUSIONS: In the current study, OC pesticides were associated with increased levels of CRP, a marker of inflammation, and both OC pesticides and PCBs may also modify the associations between CRP and insulin resistance.

Occupational causes of testicular cancer in adults

Testicular cancer is one of the commonest cancers in men of working age, and is increasing in incidence in Europe and North America. One suggested mechanism of causation is that there is impaired differentiation of germ cells in the pre- or perinatal period, followed by malignant transformation in later life, possibly by a hormonal mechanism. Endocrine disrupting chemicals [EDCs] have been a major focus of interest for etiological research into tes-ticular cancer because they interact with various hormonal pathways. Several EDCs including bisphenol A, phthalates, metals, polychlorinated biphenyls, and organochlorines have been investigated, but there are few studies and those that exist have not been able to assess exposure well. In addition, several studies, particularly those with better exposure assessment, have suggested that workers in electrical occupations have increased risks of testicular cancer. Electromagnetic radiation may have subthermal effects or may disrupt hormone release. Chronodisruption such as due to shift-work could potentially increase the risk of testicular cancer via disruption of hormonal cycles, but only one study has so far investigated this possibility. Lastly, solvent exposure, particularly to dimethylformamide, has been suggested to be associated with testicular cancer, but almost all these studies are based on job title only, with no specific assessment of solvent exposure. In conclusion, there is little evidence available on which to base definitive statements about occupational causes of testicular cancer. Future studies need to improve exposure assessment and develop ways to adjust for possible prenatal factors

Distribution of volatile organic compounds around a polluted river

The objectives of this study were to investigate the species and the concentration distribution of volatile organic compounds around a heavily polluted river. Air samples were collected seasonally at different locations near the polluted river. Samples were then analyzed by gas chromatography [electron capture detector for chlorinated organic compounds and flame ionization detector for ordinary hydrocarbons]. The data was then analyzed by the statistical product and service solutions software. The results showed that total of 26 species of volatile organic compounds were identified. Each individual had its own concentration distribution pattern at different seasons and aliphatic volatile organic compounds displayed much higher concentrations than most benzenoic volatile organic compounds. In aliphatic volatile organic compounds, 1,2-dibromo-3-chloropropane, hexachlorobutadiene and 1,2-dibromoetane had much higher concentrations at the nearby environment of the river and they have been claimed to be carcinogenic to some experimental animals and possibly to human. Therefore, It is in doubt that for a long term, the volatile organic compounds evaporating out of the stream may threat the health of the residents living very close to the river. The concentrations of tetrachloroethene, 1,1,2,2-tetrachloroethane, hexachlorobutadiene, dibromoetane, dichlorobenzene and sec-butylbenzene appeared at the nearby environment of the river had significant correlations [P < 0.05] with those of each other or many other volatile organic compounds

Organochlorine pesticides and chlorinated hydrocarbon solvents in the blood of chemically sensitive patients [corrected]. A statistical comparison with therapeutic medication and natural hormones.

The blood levels of organochlorine pesticides and chlorinated hydrocarbon solvents were measured in 200 and 114 chemically sensitive patients respectively, and compared with blood concentrations of standard medication (non- chlorinated substances. Clonidine, Haloperidol) of comparable toxicity after therapeutically effective dosage, and with reference levels of highly potent chemicals in the blood such as hormones. It was shown that the average blood levels of the most toxic environmental pollutants are comparable with the therapeutic steady state average blood levels of medications which have similar toxicities in the animal model. In addition the toxicity levels of xenoestrogens are at least an order of magnitude higher than normal plasma estrogen or progesterone levels. These findings suggest the possibility of additive or synergistic effects of these chlorinated compounds and the aforementioned medications. Also, these findings suggest the possibility of hormone deregulation from exposure to the aforementioned toxic chlorinated compounds.