OBJECTIVETo investigate the basic contents of organochlorine pesticides (DDT, BHC and HCB) in human milk of normal residents in Beijing urban areas.

METHODSThrough continuous survey on the trend of organochlorine contents in human milk since DDT and BHC pesticides were forbidden in use in 1983, and to evaluate the effects of this program, the required lying-in women residents in urban districts for at least 5 years were enrolled in this study. All these lying-in women and also their family members were not exposed to or engaged in producing or selling organochlorine pesticides. In this study, the women chosen were giving birth to a child just after one week to 4 months. The detection method used is the national standard biological detection method.

RESULTSIn 1982, the total amount of DDT and BHC contents in human milk were 6.45 mg/kg and 6.97 mg/kg, respectively, which were found the highest level in the word. The contents of organochlorine were descending apparently since the DDT and BHC pesticides were forbidden by Chinese government in 1983. According to the standards of FAO/WHO, the average intake of total DDT and beta-BHC in the infants born in 1998 was 11 and 6 microg/kg, respectively. Both of them were less than the allowable daily intake amount regulated by WHO and the Ministry of Health of Japan.

CONCLUSIONThe study might make clear that the basic levels of organochlorine pesticides (DDT, BHC and HCB) in human milk of normal residents and the attenuation trend of 2 pesticides cumulative levels in human body, through estimating the intake quantity of organochlorine by infants, showing that the DDT and BHC daily intake from human milk absorbed by infants, who were born after 1998, were at a safe level. It was indicated that the measure for forbidding use of DDT and BHC pesticides is contributory.

Adult ; China ; DDT ; analysis ; Female ; Hexachlorobenzene ; analysis ; Humans ; Hydrocarbons, Chlorinated ; analysis ; Milk, Human ; chemistry ; Pesticide Residues ; analysis ; Urban Health

Humans ; Hydrocarbons, Chlorinated ; poisoning ; Propane ; poisoning

OBJECTIVETo study the relationship between organochlorine and colorectal cancer.

METHODSWith multistage cluster random sampling, 11 towns were drawn based on the standardized incidence of colorectal cancer. Administrative and natural villages were drawn subsequently. Rice and soil samples in the paddy fields were collected in the villages. The contents of organochlorine were detected. Rank correlation analysis was performed together with the data of colorectal cancer incidence.

RESULTSThe contents of hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethane (DDT) in both rice and soil samples were below the amounts of the country. Statistics showed that the standardized incidence rates were significantly different among the 11 towns. The contents of delta-HCH, gamma-HCH, sodium pentachlorophenate in rice and those of delta-HCH in soil were statistically different among the towns through the rank sum test. The standardized incidence of colorectal cancer was significantly connected with the content of total DDT in rice while rectal cancer with total DDT and PP'-DDE and colon cancer with 1245 of polychlorinated biphenyl (PCBs). The correlation coefficients were 0.636, 0.691, 0.716 and 0.658 respectively (P < 0.05).

CONCLUSIONSRectal cancer was statistically correlated with organochlorine, mainly for total DDT and dichlorodiphenyldichloroethylene (PP'-DDE). Colon cancer was significantly associated with 1245 of PCBs. Further study should be performed since this research was only an ecological study.

Adult ; Aged ; China ; epidemiology ; Colorectal Neoplasms ; chemically induced ; epidemiology ; DDT ; adverse effects ; analysis ; Female ; Food Contamination ; analysis ; Humans ; Hydrocarbons, Chlorinated ; adverse effects ; analysis ; Incidence ; Insecticides ; adverse effects ; analysis ; Lindane ; adverse effects ; analysis ; Male ; Middle Aged ; Oryza ; chemistry ; Pesticide Residues ; adverse effects ; analysis ; Soil Pollutants ; analysis

OBJECTIVES: The study was conducted to estimate the carcinogenic risks from the ingestion of some carcinogenic pesticides (CPs) in vegetables sampled at a local agricultural product market in Seoul. METHODS: After applying a hazard identification step, we selected four pesticides, such as DDT, dieldrin, folpet, and heptachlor epoxide, for this risk assessment. Concentrations of each pesticide were measured from randomly sampled vegetables. In order to estimate the human exposure levels, we combined the concentration of pesticides in the vegetables with consumption rate of those vegetables. Three scenarios were hypothesized for human exposure assessment. Scenario I was the most conservative which supposed the undetected CPs would be the detection limit values. Scenario II was assumed that the undetected CPs would be a half of the detection limit values, and finally scenario III merely considered only values greater than the detection limit values. We finally presented the estimated carcinogenic risks on the basis of the traditional risk assessment procedure suggested by U.S. EPA. RESULTS: Pesticides including DDT, dieldrin, folpet and heptachlor epoxide were detected in 9 samples (6%) in the range of 0.0006~0.09ppm. The daily intake levels of carcinogenic pesticides were estimated in the range of 0.0009~0.0079 microgram/day. As we expected, excess cancer risks based on scenario I was also the highest (1.1x10-8~ 5.5x10-5). CONCLUSIONS: We found that the estimated risks from the pesticides we investigated were not serious. We, however, propose that a continuos monitoring is needed to make sure for the protection of public health.
DDT ; Dieldrin ; Eating ; Heptachlor Epoxide ; Humans ; Korea* ; Limit of Detection ; Pesticides* ; Public Health ; Risk Assessment* ; Seoul ; Vegetables*

Administration, Oral ; Fatal Outcome ; Humans ; Hydrocarbons, Chlorinated ; poisoning ; Propane ; poisoning

Humans ; Hydrocarbons, Chlorinated ; poisoning ; Propane ; analogs & derivatives ; poisoning

Bioremediation is one of the most effective ways to treat and dispose of chlorinated hydrocarbons, and methanotrophs are potentially useful to do so. Recent studies found that facultative methanotrophs can use compounds containing C-C bond as sources of carbon and energy, thus overcoming the limitation that obligate methanotrophsone uses only C1 compounds for this process. This is a unique metabolic approach that is becoming increasingly attractive in the field of contaminant biodegradation. Here, we summarized the bioremediation of chlorinated hydrocarbons by obligate and facultative methanotrophs. This process involves the degradation of various chlorinated hydrocarbons by diverse strains, including pure cultures and mixed cultures. We also compare the activity expression and catalytic properties of different types of methane monooxygenases in various substrates. We furthermore summarize the kinetic characteristics of the degradation of chlorinated hydrocarbons using the model strain Methylosinus trichosporium OB3b, and outline the degradation and potential of chlorinated hydrocarbons by facultative methanotrophs. Lastly, we discuss current problems and future research directions for degradation of chlorinated hydrocarbons by methanotrophs.
Biodegradation, Environmental ; Hydrocarbons, Chlorinated ; metabolism ; Methylosinus trichosporium ; metabolism ; Oxygenases ; metabolism

Female ; Humans ; Hydrocarbons, Chlorinated ; poisoning ; Male ; Middle Aged ; Occupational Diseases

Chlorinated hydrocarbons (CAHs) threaten human health and the ecological environment due to their strong carcinogenic, teratogenic, mutagenic and heritable properties. Heterotrophic assimilation degradation can completely and effectively degrade CAHs, without secondary pollution. However, it is crucial to comprehensively understand the heterotrophic assimilation process of CAHs for its application. Therefore, we review here the characteristics and advantages of heterotrophic assimilation degradation of CAHs. Moreover, we systematically summarize current research status of heterotrophic assimilation of CAHs. Furthermore, we analyze bacterial genera and metabolism, key enzymes and characteristic genes involved in the metabolic process. Finally, we indicate existing problems of heterotrophic assimilation research and future research needs.
Bacteria ; metabolism ; Biodegradation, Environmental ; Hydrocarbons, Chlorinated ; metabolism ; Industrial Microbiology ; trends

The continuous cropping obstacle of Panax notoginseng is serious, and effective control measures are lacking. Soil disinfection with chloropicrin(CP) has been proven to be effective in reducing the obstacles to continuous cropping of other crops. In order to ascertain the effect of CP in the continuous cropping of P. notoginseng, this paper explored the influences of CP at different treatment concentrations(0,30,40,50 kg/Mu, 1 Mu≈667 m~2) on soil macro-element nutrients, soil enzyme activity, growth and development of P. notoginseng, and the accumulation of medicinal components. The results showed that CP fumigation significantly increased the content of total nitrogen, alkali-hydrolyzable nitrogen, ammonium nitrogen, nitrate nitrogen, and available phosphorus in the soil, but it had no significant effect on potassium content. The soil protease activity showed a trend of first increasing and then decreasing with the prolonging of the treatment time. Both the soil urease and acid phosphatase activities showed a trend of first decreasing and then increasing with the prolonging of the treatment time. The higher the CP treatment concentration was, the lower the urease and acid phosphatase activities would be in the soil. The protease activity was relatively high after CP40 treatment, which was better than CP30 and CP50 treatments in promoting the nitrogen-phosphorus-potassium accumulation in P. notoginseng. The seedling survival rates after CP0, CP30, CP40, and CP50 tratments in October were 0, 65.56%, 89.44%, and 83.33%, respectively. Compared with the CP30 and CP50 treatments, CP40 treatment significantly facilitated the growth and development of P. notoginseng, the increase in fresh and dry weights, and the accumulation of root saponins. In summary, CP40 treatment accelerates the increase in soil nitrogen and phosphorus nutrients and their accumulation in P. notoginseng, elevates the seedling survival rate of P. notoginseng, enhances the growth and development of P. notoginseng, and promotes the accumulation of medicinal components. CP40 treatment is therefore recommended in production.
Fumigation ; Growth and Development ; Hydrocarbons, Chlorinated ; Panax notoginseng ; Soil