Women and the environment: a study of congenital limb anomalies

Lufenuron induces reproductive toxicity and genotoxic effects in pregnant albino rats and their fetuses

Insecticides and other agrochemicals have become indispensable components of the agricultural system to ensure a notable increase in crop yield and food production. As a natural consequence, chemical residues result in significantly increased contamination of both terrestrial and aquatic ecosystems. The present study evaluated the teratogenic, genotoxic, and oxidative stress effects of residual-level lufenuron exposure on pregnant rats during the organogenesis gestational period of both mother and fetus. The tested dams were divided into three groups; control (untreated), low-dose group (orally administered with 0.4 mg/kg lufenuron) and high-dose group (orally administered with 0.8 mg/kg lufenuron). The dams of the two treatment groups showed teratogenic abnormalities represented by the asymmetrical distribution of fetuses in both uterine horns, accompanied by observed resorption sites and intensive bleeding in the uterine horns, whereas their fetuses suffered from growth retardation, morphologic malformations, and skeletal deformations. Histologic examination of the liver and kidney tissues obtained from mothers and fetuses after lufenuron exposure revealed multiple histopathologic changes. DNA fragmentation and cell cycle perturbation were also detected in the liver cells of lufenuron-treated pregnant dams and their fetuses through comet assay and flow cytometry, respectively. Moreover, lufenuron-induced oxidative stress in the liver of mothers and fetuses was confirmed by the increased malondialdehyde levels and decreased levels of enzymatic antioxidants (glutathione peroxidase and superoxide dismutase). Taken together, it can be concluded that lufenuron has a great potential in exerting teratogenic, genotoxic, and oxidative stresses on pregnant rats and their fetuses upon chronic exposure to residual levels during the organogenesis gestational period. The obtained results in the present study imply that women and their fetuses may have the same risk.

Agricultural chemicals in ground water: Extent and implications

The accelerated use of agricultural chemicals over the past 20–30 years has increased production and generally has been profitable, but it has also had an adverse impact on ground water quality in many major agricultural areas. The contamination of ground water, related to nitrogen fertilizers and pesticides, from widespread, routine land application, as well as from point sources has become a serious concern. Ground water contamination also impairs surface water quality. Research, world-wide, has shown increases in NO3-N in ground water concurrent with major increases in N-fertilization. Many shallow ground water supplies now exceed recommended NO3-N drinking water standards. While many sources contribute N into the environment, synthetic fertilizers have become the major component. There are clear economic incentives to improve management; harvested crops often account for less than 50 percent of the purchased fertilizer inputs. Pesticides are appearing in ground water with unanticipated frequency, and while their concentrations are generally below acute toxic levels, many are of concern for possible chronic effects. Such widespread contamination is of real concern because of the potential for long-term and widespread exposure of the public through drinking water. Surveys of farmers indicate a desire to improve management practices and reduce chemical inputs. Promoting the principles of alternative, sustainable agriculture is a necessary element in the resolution of these problems.

Pesticide exposure: the hormonal function of the female reproductive system disrupted?

Some pesticides may interfere with the female hormonal function, which may lead to negative effects on the reproductive system through disruption of the hormonal balance necessary for proper functioning. Previous studies primarily focused on interference with the estrogen and/or androgen receptor, but the hormonal function may be disrupted in many more ways through pesticide exposure. The aim of this review is to give an overview of the various ways in which pesticides may disrupt the hormonal function of the female reproductive system and in particular the ovarian cycle. Disruption can occur in all stages of hormonal regulation: 1. hormone synthesis; 2. hormone release and storage; 3. hormone transport and clearance; 4. hormone receptor recognition and binding; 5. hormone postreceptor activation; 6. the thyroid function; and 7. the central nervous system. These mechanisms are described for effects of pesticide exposure in vitro and on experimental animals in vivo. For the latter, potential effects of endocrine disrupting pesticides on the female reproductive system, i.e. modulation of hormone concentrations, ovarian cycle irregularities, and impaired fertility, are also reviewed. In epidemiological studies, exposure to pesticides has been associated with menstrual cycle disturbances, reduced fertility, prolonged time-to-pregnancy, spontaneous abortion, stillbirths, and developmental defects, which may or may not be due to disruption of the female hormonal function. Because pesticides comprise a large number of distinct substances with dissimilar structures and diverse toxicity, it is most likely that several of the above-mentioned mechanisms are involved in the pathophysiological pathways explaining the role of pesticide exposure in ovarian cycle disturbances, ultimately leading to fertility problems and other reproductive effects. In future research, information on the ways in which pesticides may disrupt the hormonal function as described in this review, can be used to generate specific hypotheses for studies on the effects of pesticides on the ovarian cycle, both in toxicological and epidemiological settings.

Environmental equity and pesticide exposure

Although people of color and low-income groups bear a disproportionate share of the health risks from exposure to pesticides, research attention has been meager, and data on acute and chronic health effects related to their toxic exposures are generally lacking. Increased resources are needed both to study this issue and to mitigate problems already identified. People of color should be a major research focus, with priority on long-term effects, particularly cancer, neurodevelopmental and neurobehavioral effects, long-term neurological dysfunction, and reproductive outcome. Suitable populations at high risk that have not been studied include noncertified pesticide applicators and seasonal and migrant farm workers, including children.

Congenital limb deficiency: maternal factors in pregnancy

Maternal factors in pregnancy were examined in a case-control study of 155 children with limb deficiencies (longitudinal and transverse) born 1970-1981 inclusive and 274 matched normal controls. Vomiting of pregnancy was associated with an increased risk of longitudinal limb reduction defects. Gestational bleeding has long been known for its association with perinatal mortality, low birth-weight and prematurity; limb deficiencies have also been noted. In the present study the pattern of bleeding differed between women in the transverse and longitudinal groups, with the possibility of a causal role for bleeding in the aetiology of longitudinal but not transverse defects. There was a significant statistical risk associated with respiratory infections comparable with the reported association of congenital limb deficiency and influenza from Finland.