Changes in male hormone profile after occupational organophosphate exposure. A longitudinal study

There is a growing concern about the endocrine effects of long-term, low-level exposure to organophosphate (OP) compounds. Studies on experimental animals have found that OP pesticides have an impact on the endocrine system and a few clinical and epidemiological studies have also shown that OPs may affect the male hormone profile, although results are inconsistent. We have evaluated the effect of exposure to OP pesticides, measured through urinary levels of six dialkylphosphate (DAP) metabolites, on male hormone profile in 136 floriculture workers from the State of Mexico and Morelos during two agricultural periods with different degree of pesticide exposure. Generalized estimated equations (GEE) models were developed and adjusted for several potential confounders, including PON1 enzyme activity, as a biomarker of susceptibility, and serum levels of p,p'-DDE, a metabolite of the pesticide DDT widely used in Mexico until 1999 for control of agricultural pests and malaria. Exposure of male floriculture workers to OP pesticides was associated with increased serum levels of follicle-stimulating hormone (FSH) and prolactin and with decreased serum testosterone and inhibin B levels. Among all DAPs tested, only DETP was inversely associated with luteinizing hormone (LH). Estradiol showed a marginally significant positive trend with DEP and DETP derivatives. In conclusion, OP pesticides may have an impact on the endocrine function because of their potential to modify the male hormone profile as a function of the type of pesticide used as well as the magnitude of exposure.

Maternal exposure to floricultural work during pregnancy, PON1 Q192R polymorphisms and the risk of low birth weight

BACKGROUND

Although there is evidence from animal studies of impaired reproductive function by exposure to organophosphates (OP), the effects on birth weight have not been sufficiently evaluated in epidemiological studies. Paraoxonase (PON1) detoxifies organophosphates by cleavage of active oxons. Some PON1 gene polymorphisms could reduce the enzyme activity and increase susceptibility to OP toxicity.

OBJECTIVE

To assess the association between maternal exposure to floriculture during pregnancy and the risk of low birth weight (<2500 g) in their offspring, as well as to evaluate the interaction between this exposure and maternal genotype for PON1 Q192R polymorphisms.

MATERIALS AND METHODS

A cross sectional study was carried out in two Mexican states (States of Mexico and Morelos) with high frequencies of greenhouse activity. We interviewed and collected blood samples from 264 females (floriculturists or partners of floricultural workers) who became pregnant during the 10 years prior to the interview. The questionnaire measured socioeconomic characteristics, tobacco and alcohol consumption, diseases and occupational and reproductive history. We also applied a food frequency questionnaire. Information was obtained pertaining to 467 pregnancies. DNA was extracted from white cells, and PON1 genotype was determined by Restriction Fragment Length Polymorphism for Q192R polymorphisms. Results were analyzed with generalized estimating equations models.

RESULTS

After adjusting for potential confounders, we detected a statistically significant interaction between maternal exposure to flower growing work during pregnancy and PON1 Q192R polymorphisms on risk of low birth weight. The risk of having a baby with LBW is nearly six times higher if a mother is a floriculture worker during pregnancy and has PON1 192RR genotype (OR 5.93, 95% CI 1.28, 27.5).

CONCLUSION

These results suggest that the interaction between maternal floriculture work during pregnancy and 192RR PON1 genotype increases the probability of having children with LBW.

Parental occupational exposure to organic solvents and anencephaly in Mexico

OBJECTIVE

To assess the relationship between parental occupational exposure to organic solvents, and the risk of anencephaly in Mexico.

METHODS

A case-control study was conducted based on the registers of the Epidemiological Surveillance System for Neural Tube Defects in Mexico; 151 cases of anencephaly of > or =20 weeks' gestation were included. A control, born alive and without any apparent congenital malformations at birth, was selected for each case in the same maternity service in which the case was born. Information on occupational exposures, lifestyle habits, reproductive history, use of medicines, supplementation with multivitamins and folic acid, was obtained by a general questionnaire; a food frequency questionnaire was also applied to obtain information of daily intake of folate and other B vitamins. Occupational exposure to organic solvents was based on job title as a proxy for exposure and analysed considering two critical periods around conception.

RESULTS

In logistic regression analysis, the odds of having a child with anencephaly was higher if the mother or the father was occupationally exposed to organic solvents during the periconceptional period, or when both parents or at least one of them were occupationally exposed during this period with an adjusted odds ratio of 2.97 (95% CI 1.36 to 6.52).

CONCLUSIONS

The results support the hypothesis that both maternal and paternal occupational exposure to organic solvents can increase the probability of having a child with anencephaly.

Maternal and paternal occupational exposure to agricultural work and the risk of anencephaly

AIMS

To evaluate the association between parental occupational exposure to agricultural work and the risk of anencephaly in three Mexican states.

METHODS

A paired case control study (1:1) was done based on records of the Epidemiological Surveillance System of Neural Tube Defects in Mexico; 151 cases of anencephaly of more than 20 weeks' gestation were selected between March 2000 and February 2001. Controls were selected from the same maternity services as those of the cases and were born alive without congenital malformations. Information was obtained from both parents by means of a general questionnaire, a food frequency questionnaire, and a specific questionnaire on occupational exposure to pesticides. Exposures were analysed with emphasis on the three months before and one month after the last menstruation periods (acute risk period (ARP)), as well as exposure prior to the above mentioned period (non-acute risk period (NARP)).

RESULTS

The children of mothers who worked in agriculture in the ARP had a greater risk of anencephaly (OR = 4.57, 95% CI 1.05 to 19.96). The risk of fathers having a child with anencephaly was greater in those who applied pesticides irrespective of whether it was done in the ARP or the NARP (OR = 2.50, 95% CI 0.73 to 8.64; and OR = 2.03, 95% CI 0.58 to 7.08, respectively).

CONCLUSIONS

These results support the hypothesis of the effect of maternal exposure to agricultural work on anencephaly and suggest that exposure of the father to pesticides in the periconceptional period or prior to this can also increase the risk of having an anencephalic child.

[Tolerance and resistance: abortion from the point of view of traditional midwives in a rural area of Mexico]

OBJECTIVE

An evaluation of the perception, resources and practices regarding abortion of traditional midwives in a rural area in the municipality of Yecapixtla, state of Morelos, located in the central region of Mexico.

METHODS

A qualitative methodology consisting of a detailed interview, focal groups and participating observation, was used. The subjects investigated were socio-cultural aspects, reproduction, sexuality and health related to abortion. Nine midwives were interviewed and a focal group was formed in which 16 midwives participated.

RESULTS

The results demonstrated a profound rejection of abortion whether inducted or spontaneous. The former was considered a major sin and the latter a serious failure of a womańs reproductive function. Women who abort are called "pigs", "hogs" or "bitches" and the midwives are reluctant to attend them. However, a common practice among the women in the community is to "regulate the menstruation", that is, to use substances that provoke menstruation when this is delayed. This specific practice is not considered abortive by these women.

CONCLUSION

Local popular beliefs about abortion are indispensible for the construction of effective strategies, which when provided by the institutional health services, reinforce the bonds between these and the traditional midwives in such a way as to increase accessibility to the health services as well as the quality of care to women.

[Violence and its repercussions on health: theoretical reflections and magnitude of the problem in Mexico]

Our understanding of violence gains from perspectives contributed by several different disciplines. The differences among goals and points of view are often reflected in their vocabularies and interfere in to integrate the advances by each of them. Three big disciplines have studied violence, those are: Social Sciences, Criminal Justice and most recently Public Health. This paper discusses the theoretical perspectives by discipline and try to dimensionate the violence problem measured by mortality and morbidity by intentional injuries in México.