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.

Circadian nursing induces PER1 protein in neuroendocrine tyrosine hydroxylase neurones in the rabbit doe.

Rabbit does nurse their pups once a day with circadian periodicity and pups ingest up to 35% of their body weight in milk in < 5 min. In the doe, there is a massive release of prolactin. We hypothesised that periodic suckling synchronises dopaminergic populations that control prolactin secretion. We explored this by immunohistochemical colocalisation of PER1 protein, the product of the clock gene Per1 on tyrosine hydroxylase (TH) cells in three dopaminergic populations: tuberoinfundibular dopaminergic (TIDA), periventricular hypophyseal dopaminergic (PHDA) and incertohypothalamic dopaminergic (IHDA) cells. PER1/TH colocalisation was explored every 4 h through a complete 24-h cycle at postpartum day 7 in does that nursed their pups either at 10.00 h (ZT03) or at 02.00 h (ZT19; ZT0 = 07.00 h, time of lights on). Nonpregnant, nonlactating females were used as controls. In control females, there was a rhythm of PER1 that peaks at ZT15. By contrast, in nursed does, the PER1 peak shifted in parallel to scheduled nursing in TIDA and PHDA cells but not in IHDA cells, which are not related to the control of prolactin. Next, we determined that the absence of suckling for 48 h significantly decreases the number of PER1/TH colocalised cells in PHDA but not TIDA cells. Locomotor behaviour in control subjects was maximal at around the time of lights on but, in nursed females, shifted at around the time of scheduled nursing. Finally, in the suprachiasmatic nucleus, there is a maximal expression of PER1 at ZT11 in the three groups. However, this maximal expression was significantly lower in the nursed groups in relation to the control group and in the groups deprived of nursing for 48 h. We conclude that suckling synchronises dopaminergic cells related to the control of prolactin and appears to be a nonphotic stimulus for the suprachiasmatic nucleus.

Organochlorine pesticide gradient levels among maternal adipose tissue, maternal blood serum and umbilical blood serum.

The objective of the present study was to determine levels and calculate ratios of copartition coefficients among organochlorine pesticides ß-HCH, pp'DDE, op'DDT and pp'DDT in maternal adipose tissue, maternal blood serum and umbilical blood serum of mother-infant pairs from Veracruz, Mexico. Organochlorine pesticides were analyzed in 70 binomials: maternal adipose tissue, maternal serum and umbilical cord serum samples, using gas chromatography with electron capture detection (GC-ECD). The results were expressed as mg/kg on fat basis. p,p'-DDE was the major organochlorine component, detected in every maternal adipose tissue (0.770 mg/kg), maternal serum sample (5.8 mg/kg on fat basis) and umbilical cord blood sample (6.9 mg/kg on fat basis). p,p'-DDT was detected at 0.101 mg/kg, 2.2 mg/kg and 5.9 mg/kg respectively, according to the order given above. ß-HCH was detected at 0.027 mg/kg, 4.2 mg/kg and 28.0 mg/kg respectively. op'DDT was detected only in maternal adipose tissue at 0.011 mg/kg. The copartition coefficients among samples identify significant increases in concentrations from adipose tissue to maternal blood serum and to umbilical blood serum. The increase indicated that maternal adipose tissue released organochlorine pesticides to blood serum and that they are carried over to umbilical cord blood.

Organochlorine pesticide levels in umbilical cord blood of newborn in Veracruz, Mexico.

Organochlorine pesticides accumulate in lipid rich compartments of organisms. During pregnancy, the compounds pass through the placental barrier appear in cord blood. The aim of this study was to monitor the levels of organochlorine pesticides in 70 umbilical cord blood samples taken during deliveries in Veracruz in 2009. For organochlorine pesticides, only the presence ß-HCH (4%, 3.9 µg/L median concentration on wet weight), pp'DDE (100%, 0.7 µg/L) and pp'DDT (4%, 1.4 µg/L) were detected. The total pool of samples divided according to sex of new born babies, showed no statistical differences among median concentrations. The number of deliveries considered as a determinant contamination factor affirmed there were no statistical differences among median concentrations; however pp'DDE levels increased from the one to two childbirth groups. Age of pregnant women as a discriminate factor manifests in a significant increase in contamination levels among first, second and third tertile. In general, umbilical cord blood samples in Veracruz contained organochlorine pesticides, especially pp'DDE, confirming the presence of these compounds in the environment and their transfer from the mother to the developing fetus.

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.

Breast milk excretion Kinetic of b-HCH, pp'DDE and pp'DDT.

Breast milk is considered the most important route in the elimination of deposited organochlorine pesticides in a mother's body. The equilibrium of organochlorine pesticides in the human body considers the elements of internal transport processes, the equilibrium pattern between pesticides and tissue fat contents, and the mobilization of lipids and lipoproteins among body parts. The aim of this study was to determine organochlorine pesticide levels in breast milk samples from the 4th to the 30th day of lactation and the trend in their concentration time so as to forecast the time tendency of residue levels and the pesticide excretion pattern. Milk samples were taken from forty participants and analyzed by GLC-ECD. The organochlorine pesticide residues determined in the breast milk samples during lactation decreased: ß-HCH from 0.095 to 0.066 mg/kg, pp'DDE from 1.807 to 1.423 mg/kg and pp'DDT from 0.528 to 0.405 mg/kg, at the characteristic rate for each compound. The obtained results compared with the calculated fits of forecasts were parallel and did not exhibit significant differences. The newborn baby exposed during lactation had organochlorine pesticide residues whose levels decreased permanently. The levels depended not only on the breast milk nutrition, but also on the total environmental exposures which included air pollution as a significant contamination source.

DDT and HCH isomer levels in soils, carrot root and carrot leaf samples.

Agricultural cultivation assists organochlorine pesticide migration from contaminated soils to growing plants. This phenomenon is caused by retention processes that modify volatile pesticide exchange between soil, air and plants. The aim of the study was to monitor organochlorine pesticide (HCB, alpha- and gamma-HCH, pp'DDE, op'DDT, pp'DDT) levels and compare these concentrations in soil, carrot roots and carrot leaves. Fifty soil samples, 50 carrot root and 50 carrot leaf samples were taken from the same fields and analyzed by GLC-ECD. The results reveal organochlorine pesticide diffusion from agricultural soils to growing carrot plants and their vapors adsorption by leaves. Within the carrot plant, organochlorine pesticides accumulate especially in carrot root peel, 3-7 times more than in root flesh.

Persistent organochlorine pesticide levels in bovine fat from Mexico.

Organochlorine pesticides have been used in Mexico in agriculture as a seed dresser, in sanitation, in malaria control programmes and in livestock to combat ectoparasites. The pesticides applied drift to areas where cattle graze and plants grow. Because of their chemical stability, they accumulate in the lipid-rich tissues of the body. In the body, they circulate throughout all compartments and accumulate in adipose fat. The aim was to monitor the organochlorine pesticide levels in bovine muscle fat and kidney fat from cows living in an endemic malaria zone, where the environmental contamination can be suspected as being higher. Two hundred samples (100 muscle fat, 100 kidney fat) were analysed by gas chromatography. From the pesticides, only hexachlorobenzene (HCB), beta-hexachlorocyclohexane (HCH), gamma-HCH, pp'-1.1.1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT), op'-DDT and pp'-DDE, were detected frequently and at levels above the detection limits. The HCB mean level was low at 0.009 mg kg(-1) on a fat basis. From the HCH isomers, beta-HCH mean concentration was 0.039 mg kg(-1) and gamma-HCH was 0.025 mg kg(-1) on a fat basis. Among DDTs, pp'-DDT was the major constituent (0.032 mg kg(-1) on a fat basis) followed by pp'-DDE (0.025 mg kg(-1) on a fat basis) and op'-DDT (0.023 mg kg(-1) on a fat basis). The DDT total (sigma DDT) level was 0.067 mg kg(-1) on a fat basis. Comparing the previous study (1994) and the present one (2002-03), organochlorine pesticide levels were decreased. HCB decreased 3.7 times from 0.033 to 0.009 mg kg(-1) on a fat basis; beta-HCH decreased 3.8 times from 0.149 to 0.039 mg kg(-1) on a fat basis; pp'-DDE did not reveal a significant difference at 0.026 versus 0.025 mg kg(-1) on a fat basis. However, pp'-DDT decreased substantially, 6.7 times from 0.215 to 0.032 mg kg(-1) on a fat basis. The DDT total decreased 3.5 times from 0.236 to 0.067 mg kg(-1) on a fat basis. The tendency for reduced concentrations in organochlorine pesticide levels in Mexican cows is caused by their substitution with pyrethroids used in agriculture and by the Mexican Ministry of Health in sanitary programmes.

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.

Persistent organochlorine pesticide levels in cow's milk samples from tropical regions of Mexico.

Organochlorine pesticides have been used in agriculture as a seed dresser, in sanitation, in malaria control programmes and in livestock to combat ectoparasites. Their residues accumulate in lipid-rich tissues due to their chemical stability and persistence. In the body they circulate throughout all compartments, deposit themselves in adipose fat and can be excreted during lactation. These pesticides are applied in tropical zones and drift to areas where cattle graze. Therefore, analyses of cow's milk samples can serve as an indicator of environmental and cows' exposure to them. One hundred and fifty milk samples were taken each year in 1998 and 2001 and analysed to determine concentrations of HCB, beta-HCH, pp"-DDE, op'-DDT and pp'-DDT. Results obtained indicate that beta-HCH is one of the main contaminants (0.106 and 0.087 mg x kg(-1) on fat basis) followed by pp'-DDT (0.078 and 0.037 mg x kg(-1) on fat basis) and pp'-DDE (0.051 and 0.033 mg x kg(-1) on fat basis). The HCB and op'-DDT were detected in lower quantities respectively (0.008 and 0.006 mg x kg(-1), and 0.031 and 0.010 mg x kg(-1) on fat basis). When comparing the results obtained with those from the previous study, it was noted that DDT levels decreased significantly in 2001 as a result of the substitution of the organochlorine insecticides with pyrethroids sprayed by the Mexican Ministry of Health to combat malaria since 1999.

Organochlorine pesticide levels in maternal adipose tissue, maternal blood serum, umbilical blood serum, and milk from inhabitants of Veracruz, Mexico.

Organochlorine pesticides, due to their persistence, accumulate in food chains and cause elevated contamination in human beings. These residues bioconcentrate in lipid-rich tissues according to the equilibrium pattern of internal transport and lipid tissue content. The analyses of maternal adipose tissue, maternal blood serum, umbilical blood serum, colostrum, and mature milk indicate circulation of these compounds through all compartments of the maternal body, including their crossover of the placental barrier. The greatest residue levels found correspond to DDTs, with highest levels determined in colostrum (5.71 mg/kg of DDT total), followed by adipose tissue with 5.66 mg/kg and in mature milk with 4.70 mg/kg. Among DDTs, pp'DDE is the most predominant compound. The paired analyses of organochlorine pesticide residue levels between mother blood serum and umbilical blood serum demonstrate significant correlation and their transfer from mother to fetus through the placenta. The paired analyses of adipose tissue and colostrum and mature milk contamination levels indicate a high degree of coherence, principally of DDT, in the body and lactation as a decontamination means.

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.