Aerial pesticide application causes DNA damage in pilots from Sinaloa, Mexico.

The use of pesticides in agricultural production originates residues in the environment where they are applied. Pesticide aerial application is a frequent source of exposure to pesticides by persons dedicated to agricultural practices and those living in neighboring communities of sprayed fields. The aim of the study was to assess the genotoxic effects of pesticides in workers occupationally exposed to these chemicals during their aerial application to agricultural fields of Sinaloa, Mexico. The study involved 30 pilots of airplanes used to apply pesticides via aerial application and 30 unexposed controls. Damage was evaluated through the micronucleus assay and by other nuclear abnormalities in epithelial cells of oral mucosa. The highest frequency ratios (FR) equal to 269.5 corresponded to binucleated cells followed by 54.2, corresponding to cells with pyknotic nuclei, 45.2 of cells with chromatin condensation, 3.7 of cells with broken-egg, 3.6 of cells with micronucleus, and 2.0 of karyolytic cells. Age, worked time, smoking, and alcohol consumption did not have significant influence on nuclear abnormalities in the pilots studied. Pesticide exposure was the main factor for nuclear abnormality results and DNA damage. Marked genotoxic damage was developed even in younger pilots with 2 years of short working period, caused by their daily occupational exposure to pesticides.

Organochlorine pesticide levels in adipose tissue of pregnant women in Veracruz, Mexico.

DDT and Lindane (gamma-HCH) which were used until 1999 in Mexico, have provided great benefits in the combat of vectors that spread infection-borne diseases and in agriculture for crop protection. The persistence in the environment and their accumulative properties results in bioconcentration in lipid rich tissues of the human body that reflect the extent of environmental pollution. Human adipose tissue samples were taken during 2009 from abdominal cavities of 69 pregnant women by cesarean surgery and from 34 samples of control donors by autopsy in Veracruz State. The samples were analyzed by gas chromatography with ECD. The results of mean levels (mg/kg on fat basis) were higher in controls compared to pregnant women beta-HCH 0.064 vs 0.027; pp'DDE 1.187 vs. 0.745; op'DDT 0.016 vs. 0.011; pp'DDT 0.117 vs. 0.099 and Sigma-DDT 1.337 vs. 0.854. The pregnant women group was divided according to age: up to 20, 20-30, and more than 30 years, and presented an increase for the more persistent pesticides with age in terms of mean concentrations and a more pronounced higher correlation in medians levels. Pairing Body Mass Index to organochlorine pesticide mean levels revealed no correlation between these factors in pregnant women.

Persistent organochlorine pesticides in Mexican butter.

Organochlorine pesticides have been used in Mexico in malaria control programmes against ectoparasites and as seed dresser. Owing to their chemical stability, they tend to accumulate in the lipid part of the organisms. The stored pesticides are excreted with the endogenous fat during milk production. The aim was to monitor the organochlorine pesticide levels in butter manufactured in Mexico. From the pesticides, only HCB, beta-HCH, pp'-DDT, op'-DDT and pp'-DDE with major frequency and levels were detected. The HCB mean level was low at 0.008 mg kg(-1) on a fat basis. From the HCH isomer, only the beta-HCH at 0.065 mg kg(-1) on a fat basis was determined, remaining as the main contaminant of the monitored butters. Among DDTs, pp'-DDE was the major constituent (0.043 mg kg(-1) on a fat basis) followed by pp'-DDT (0.036 mg kg(-1)) and op'-DDT (0.009 mg kg(-1)). Comparing the previous study (1994) and this one (2001), all organochlorine pesticides had a descendent tendency; beta-HCH decreased from 0.095 to 0.065 mg kg(-1) on a fat basis, whereas the total DDT decreased from 0.056 to 0.047 mg kg(-1), pp'-DDT from 0.050 to 0.036 mg kg(-1), op'-DDT from 0.018 to 0.009 mg kg(-1), while pp'-DDE increased from 0.032 to 0.043 mg kg(-1). The decreased DDT levels in Mexican butters is caused by the substitution of organochlorine insecticides with pyrethroids used by the Mexican Ministry of Health since 1999 in sanitary programmes.

Carry-over of persistent organochlorine pesticides through placenta to fetus.

OBJECTIVE: As a consequence of environmental exposure, organochlorine pesticides accumulate in lipid rich-tissues such as maternal adipose tissue and partition to maternal blood serum and umbilical blood serum. To establish their distribution in the human body, the concentration gradients of organochlorine pesticides between these compartments were determined. MATERIAL AND METHODS: Maternal adipose tissue, blood serum and umbilical blood serum samples from 64 volunteers admitted for cesarean delivery at Hospital Benito Coquet Lagunes were studied in Veracruz during 1997 and 1998. The pesticide residues were determined by gas chromatography and results obtained from different sample groups were analyzed using Pearson correlation coefficients and simple lineal regression. RESULTS: Significant results expressed on fat basis of organochlorine pesticides indicate that 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT) levels are higher in maternal adipose tissue (4.51 mg/kg DDE and 1.27 mg/kg pp'DDT), maternal blood serum (4.45 mg/kg DDE and 0.78 mg/kg pp'DDT), and umbilical blood serum (4.70 mg/kg DDE and 0.88 mg/kg pp'DDT), due to greater affinity of DDT for lipids. CONCLUSIONS: The statistical evaluation of results and the pairing of samples analyzed indicate that absorbed organochlorine pesticides cross the placental barrier and reach a balanced state between mother and fetus.

Levels of organochlorine pesticides in Mexican butter.

Organochlorine pesticide residues were analyzed in 345 samples of butter purchased from Mexican supermarkets in 1994. Three national brands and one foreign brand were analyzed. Most samples contained residues of gama-HCH (91%), HCB (90%), and p,p'-DDE (88%). Residues of alpha-HCH (63%), p,p'-DDT (42%), beta-HCH (38%), o,p'-DDT (17%), heptachlor epoxide (7%), and endosulfane sulfate (3%) were also detected. Mean values of pesticide residues determined were 0.093 mg/kg fat for total HCH and 0.056 mg/kg for total DDT. Mean values of organochlorine pesticide residues in Mexican butter were comparable with those in a foreign brand.

Detection of some organochlorine pesticides in cow's milk.

This monitoring study of 192 samples of cow's milk collected from the central region of Veracruz state was conducted to determine the contamination levels of organochlorine pesticides. The results obtained for mean DDT and HCH levels were 0.057 and 0.098 mg/kg respectively expressed on fat basis and are within FAO tolerances and similar to those found in other tropical countries.

Chlorinated pesticide residues in testicular tissue samples. Pesticides in human testicles.

Residues of chlorinated pesticides--HCB, alpha-, beta-, gamma-, delta-, epsilon-HCH isomers, heptachlor epoxide, DDE and DDT isomers in bilateral testicular biopsy material were determined in gas liquid chromatography with electron capture detector (GLC-ECD). The average levels of chlorinated pesticides residues occurring in 36 men are presented. Alpha-, delta-HCH and p,p'-DDE were observed in nearly all analyzed samples. Other analyzed compounds were observed in lower percentages, whereas o,p'-DDT and p,p'-DDT were not detected.

Simple, low-cost method for determination of selected chlorinated pesticides in fat samples.

A method is described for the quantitative and qualitative determination of selected chlorinated pesticides in fat samples. Pesticides residues are extracted with petroleum ether and separated from fat with concentrated H2SO4 instead of the commonly used adsorbents Florisil, alumina, or silica gel. Residues were analyzed by gas chromatography with electron capture detection. Recoveries of fortified samples were approximately 100%.

Content of chlorinated pesticides in human semen of a random population.

Residues of chlorinated pesticides--BHC isomers, DDT isomers, HCB and DMDT--in samples of human semen have been determined. Samples of semen were collected from a random population of patients sent to our department for the evaluation of their fertilizing ability. The contents of 50 samples of semen were analyzed individually for residues of chlorinated pesticides and their metabolites by gas-liquid chromatography. Of BHC isomers detected in the analyzed samples of semen, the highest absolute values were shown for epsilon-BHC (mean 0.005 microgram/g of sample). DMDT, op'DDT and pp'DDt were not detected in the studied samples. DDE was found in 20 samples on the average level of 0.003 microgram/g.

Comparison of the content of chlorinated pesticide residues in human semen, testicles and fat tissues.

Studies were undertaken to determine the residues of chlorinated pesticides in human semen, testicles and fat tissues. Samples of semen were taken from a random population and samples of tissues at surgery. A preliminary estimation was made to assess the level gradient of environmental pollutants in these types of specimens characterized by a different fat content. Pesticides were considered to show an affinity to fat. The results are an early stage in a programme for a detailed analysis of the effect of pesticides on human reproductive ability and on the value of genetic material.