Environmental Pollutants ; Humans ; Polychlorinated Biphenyls ; Population Surveillance

In this review, we have provided an overview of the environmental risk factors for attention deficit hyperactivity disorder (ADHD), focusing on the major environmental toxicants related to the disorder. Researchers have indicated that since the characteristics of ADHD are complex, the disorder's etiology involves multiple genes of moderate effect interacting with environmental factors. The possible roles of prenatal and perinatal exposure have been the main focus of research on environmental risk factors for ADHD. Among environmental toxicants, we reviewed the potential effects on the development of ADHD of exposure to lead, nicotine, alcohol, polychlorinated biphenyls (PCBs), and dioxin. Further, for the each neurotoxicant, clinical prevention or intervention strategies aimed at reducing a child's risk from environmental toxic insults have been presented.
Attention Deficit Disorder with Hyperactivity ; Nicotine ; Polychlorinated Biphenyls ; Risk Factors

OBJECTIVETo compare the nature of the metabolites formed from the phase I metabolism (hydroxylation and oxidation) and phase II metabolism (glutathionyl conjugation) of PCBs that have different chlorine substitution patterns. To discuss the structure-activity relationships and metabolic mechanisms of PCBs.

METHODS4-Cl-biphenyl (PCB3), 4,4'-Cl-biphenyl (PCB15), 3,4,3',4'-Cl-biphenyl (PCB77) were used for in vitro metabolic study. LC/MS and UV-Vis studies were performed for metabolites identification.

RESULTSThe cytochrome P-450 catalyzed hydroxylation rate decreased as the number of chlorine substitutions increased. In this reaction, PCB3 was fully metabolized, approximately half of the PCB15 was metabolized and PCB77 was not metabolized at all. The oxidation rate of PCB15-HQ was higher than that of PCB3-HQ under various oxidation conditions. The LC/MS and UV-Vis data suggest that in the conjugation reaction of PCB15-Q and GSH, the Michael addition reaction occurs preferentially over the displacement reaction.

CONCLUSIONThe metabolic profiles of polychlorinated biphenyls (PCBs) are dramatically affected by chlorine substitution patterns. It is suggested that the metabolic profiles of PCBs are related to their chlorine substitution patterns, which may have implications for the toxicity of PCB exposure.

Hydroxylation ; Molecular Structure ; Oxidation-Reduction ; Polychlorinated Biphenyls ; chemistry

Polychlorinated biphenyls (PCBs) are a class of persistent organic pollutants with estrogen-like effects that exist widely in the environment, and its male reproductive toxicity is arousing more and more attention. Studies indicate that different types of cells in the testis respond differently to PCBs exposure. This article presents an overview on the toxicity of PCBs to testicular germ cells, Leydig cells, Sertoli cells and male offspring. We suggest that deeper studies focus on the mechanism of PCBs according to the results of investigations on male reproductive epidemiology. An insight into the intercellular junctions of Sertoli cells might produce a breakthrough in the studies of the testicular toxicity of PCBs.
Animals ; Leydig Cells ; drug effects ; Male ; Polychlorinated Biphenyls ; toxicity ; Sertoli Cells ; drug effects ; Testis ; drug effects

OBJECTIVETo study the effect of polychlorinated biphenyl, Aroclor1254 on benzo (a) pyrene [B (a) P]-induced DNA damage in HepG2 cells.

METHODSHepG2 cells were pretreated with Aroclor1254 (11.5, 23 and 46 micromol/L) for 24 hours and then exposed to B (a) P (50 micromol/L). DMSO (10 ml/L) was used as solvent control. Single cell gel electrophoresis (SCGE) and high-performance liquid chromatography-electrochemical detection (HPLC-EC) assays were applied to detect DNA single-strand breaks and 8-hydroxy-2'-deoxyguanosine (8-OHdG) in HepG2 cells, respectively.

RESULTSAverage Oliver tail moment (OTM) and 8-OHdG level in HepG2 cells were significantly increased in B (a) P treated group (1.66 +/- 0.21), (23.31 +/- 6.02) 8-OHdG/10(6)dG than that in solvent control (0.79 +/- 0.15), (12.31 +/- 3.24) 8-OHdG/10(6)dG, respectively. In Aroclor 1254 treated group (11.5, 23.0, 46.0 micromol/L), average OTM were 0.88 +/- 0.20, 1.01 +/- 0.15 and 1.10 +/- 0.16, and 8-OHdG levels were (19.57 +/- 7.57), (22.80 +/- 9.16) and (31.74 +/- 9.25) 8-OHdG/10(6)dG, respectively. A concentration of 46 micromol/L Aroclor1254 caused a significant increase of 8-OHdG level as compared with the solvent control. After pretreatment of HepG2 cells with Aroclor1254 (11.5, 23.0 and 46.0 micromol/L), B (a) P induced more DNA strand breaks (OTM: 2.14 +/- 0.22, 2.43 +/- 0.32 and 2.71 +/- 0.31) and 8-OHdG [(32.50 +/- 3.81), (49.23 +/- 16.66) and (60.36 +/- 18.04) 8-OHdG/10(6)dG] in HepG2 cells than B (a) P alone.

CONCLUSIONAroclor1254 might enhance B (a) P-induced DNA damage in HepG2 cells, which should imply a synergistic effect of Aroclor1254 on the genotoxicity of B (a) P.

Benzo(a)pyrene ; toxicity ; Cell Line, Tumor ; DNA Damage ; drug effects ; Drug Synergism ; Humans ; Polychlorinated Biphenyls ; toxicity

OBJECTIVETo analyse the levels of polychlorinated dibenzo-p-dioxins and dibenzo-furans (PCDD/Fs) in sea fish samples in some sea area in China surveyed by using isotope dilution HRGC/HRMS and was evaluated the local people with PCDD/Fs exposure from eating fish.

METHODSSeven different kinds of fish and twenty fishes were sampled totally. Dibenzo-p-dioxins and dibenzo-furans were extracted from fish samples by Soxhlet extraction, concentrated and purified by FMS column chromatograph and enriched by carbon column. Confirmation and quantitative analysis at ng/kg level of PCDD/Fs was performed by HRGC/HRMS using multiple ion detection mode (MID).

RESULTSCarp-2 was the certified reference material obtained from the NRC Institute of Canada. The concentration of 9 compounds was consistent with the certified value, and precision was evaluated in this study. The relative standard deviation was less than 15 percent for three times determination. The average concentration of 20 sea fishes was 1.48 ng/kg wet weight, the range was in 0.21-8.10 ng/kg wet weight, and the average total toxicity equivalency factor (TEQ) was 0.292 ng TEQ/kg (wet weight basis) and the range was 0.030-1.291 ng TEQ/kg for these 20 fishes. The evaluation exposure from fish for local people was 0.58 pg WHO-TEQ/kg BW.day.

CONCLUSIONThe levels of PCDD/Fs was different from sample to sample, and the exposure from fish be less than WHO tolerance limit standard, however, the status for PCDD/Fs pollution should not be ignored especially when having an intake of multi-food.

Animals ; Benzofurans ; analysis ; China ; Dioxins ; analysis ; Environmental Pollutants ; analysis ; Fishes ; Polychlorinated Biphenyls ; analysis ; Seafood ; analysis

Chloracne is a refractory acneiform eruption due to halogenated polyaromatic compound(eg. dioxin, dibenzofurans, polychlorinated biphenyls, etc.). 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin, a kind of dioxin isomer, contained in the Agent Orange which was used for defoliating agent during Vietnam war. It is characterized by recalcitrant comedones and cyst predominantly in the malar and postauricular area. Lesions of the penis and scrotum are also relatively frequent. The key pathological feature is the non-inflammatory keratinization of pilosebaceous unit. The meibomian glands are typically affected. Xerosis, conjunctivitis, pigmentation, follicular hyperkeratosis, actinic elastosis are occasionally associated with chloracne. We report a case of typical chloracne due to exposure to defoliating agent during Vietnam war in a 54-year-old-man who shows typical clinical and histopathological features.
Acneiform Eruptions ; Actins ; Chloracne* ; Citrus sinensis ; Conjunctivitis ; Male ; Meibomian Glands ; Penis ; Pigmentation ; Polychlorinated Biphenyls ; Scrotum ; Vietnam*

BACKGROUND: Persistent organic pollutants (POPs) are toxic materials that cannot be broken down naturally and that easily accumulate in the body. Although several studies have attempted to reveal the effects of POPs on the endocrine and nervous system and on cancer, few studies focus on the relationship between low-dose POPs and public health. We attempted to find a relationship between the level of POPs and common gastrointestinal symptoms, including abdominal discomfort, diarrhea, and constipation. METHODS: We recruited 121 subjects who visited Kyungpook National University Hospital for a health screening. Plasma concentrations were evaluated for 40 kinds of POPs including 17 types of polychlorinated biphenyls and 23 types of organochlorine pesticides. Furthermore, the Korean version of the Rome III criteria was used to identify gastrointestinal symptoms. RESULTS: Our results showed that abdominal discomfort had an inverse relationship with several polychlorinated biphenyls. Moreover, an inverted U-shaped relationship was observed between abdominal discomfort and several other organochlorine pesticides including p,p'-dichlorodiphenyldichloroethane and p,p'-dichlorodiphenyltrichloroethane, and the effects of these pesticides on abdominal discomfort were similar to that of organochlorine pesticides on obesity and metabolic syndrome. CONCLUSION: Our results suggest that mild and unspecified gastrointestinal symptoms with no clear cause could be related to POPs levels.
Constipation ; Diarrhea ; Gyeongsangbuk-do ; Mass Screening ; Nervous System ; Obesity ; Pesticides ; Plasma ; Polychlorinated Biphenyls ; Public Health

For the previous century, the humans have created an unintended and unwanted problem of endocrine disruptors as a potential threat to our public health. By the name of industrialization, endocrine disruptors are smuggling in the everyday life of people today. Although there are much debate on the reality of their emerging health threat, it is no doubt that there are certain classes of compounds that have the potential to affect hormonal status adversely, leading to abnormal development, reproductive dysfunction, and some cancers. The classes of endocrine disruptors are extensively diverse and even more increasing, such as, polychlorinated biphenyls (PCBs), dioxins, dieldrin, bisphenol A and toxaphene. Although these endocrine disruptors have been prohibited or tightly regulated, many of them are still unrecognized and still used without knowing their potential threat to the biological world. Once they are released into the environment, they usually persist without degradation and even undergo bioaccumulation and bioconcentration in food chain. Comparing with the great concern over the public health, we do not have enough information for these issues. It is now clear that we need further extensive studies for the risk assessment and the protection of human and ecological health from the potential hazards of endocrine disruptors. This article introduces a breif overview of the current status of our knowledge and research on endocrine disruptors.
Dieldrin ; Dioxins ; Endocrine Disruptors* ; Food Chain ; Humans ; Polychlorinated Biphenyls ; Public Health ; Risk Assessment ; Toxaphene

Endocrine disrupting chemicals (EDCs) are exogenous chemicals contained in industrial substances and plasticizers commonly utilized worldwide. Human exposure to such chemicals, particularly at low-doses, is omnipresent, persistent, and occurs in complex mixtures. EDCs include bisphenol A, phthalates, pesticides, and persistent organic pollutants such as polychlorinated biphenyls. Burgeoning epidemiological, animal, and cellular data link environmental EDCs to metabolic dysfunction. In the last three decades, the number of diabetic patients has drastically increased worldwide, with current statistics suggesting that the number will double in the next two decades. There is epidemiological and experimental evidence linking background exposure to a selection of environmental EDCs with diabetes and impaired glucose metabolism. EDC may be related to increased risk of diabetes.
Animals ; Complex Mixtures ; Endocrine Disruptors ; Environmental Pollution* ; Glucose ; Humans ; Metabolism ; Pesticides ; Plasticizers ; Plastics ; Polychlorinated Biphenyls