Dichlorvos-impregnated resin strips (DDVP pest strips) are among the few organophosphate products still available for indoor residential use. The residential uses for most other organophosphate products, including most DDVP products, were canceled because they posed unreasonable risks to children. DDVP pest strips act by inhibiting acetylcholinesterase activity in the brain and nerves of insect pests and are designed to gradually release DDVP vapor for up to 4 months. Acute illnesses in humans associated with nonlethal acute exposures usually resolve completely, but recovery is not always rapid. To assess the frequency of acute illnesses associated with DDVP pest strips, cases from 2000 through June 2013 were sought from the 12 states that participate in the Sentinel Event Notification System for Occupational Risks (SENSOR)-Pesticides Program, the National Pesticide Information Center (NPIC), and Health Canada.* A total of 31 acute DDVP pest strip-related illness cases were identified in seven U.S. states and Canada. The majority of these illnesses resulted from use of the product in commonly occupied living areas (e.g., kitchens and bedrooms), in violation of label directions. Although 26 of the 31 cases involved mild health effects of short duration, five persons had moderate health effects. Illnesses caused by excess exposure to DDVP pest strips can be reduced by educating the public about the proper usage of DDVP pest strips and with improvements in label directions.
Dietary exposure to persistent organochlorine compounds (POCs) has been found to affect the menstrual cycle in both animals and humans. In Sweden, the major exposure route for POCs is the consumption of fatty fish from the Baltic Sea. Thus, women who eat relatively large amounts of this fish constitute a suitable study group when investigating a possible association between dietary exposure to POC and menstrual cycle disruption. Questionnaires were sent to the exposed women, as well as to a socioeconomically similar cohort of controls, and information was collected on their menstrual cycles. Since the exposed women tended to smoke more than the controls, all results were adjusted for smoking habits. A cohort comparison found that the exposed women on average had 0.46 (95% confidence interval: 0.03, 0.89) days shorter menstrual cycles than controls. However, within the exposed cohort no effects were found of the proxy variables early life exposure and high consumption of Baltic Sea fatty fish. The results give some support to previous results from studies on women with similar exposure, but are not conclusive with respect to whether there is a causal association between POC exposure and menstrual cycle disruption.
The pesticide metabolite p,p'-DDE has been associated with left ventricular (LV) mass and known risk factors for LV hypertrophy in humans and in experimental models. We hypothesized that the associations of p,p'-DDE with LV hypertrophy risk factors, namely elevated glucose, adiposity and hypertension, mediate the association of p,p'-DDE with LV mass.
p,p'-DDE was measured in plasma from 70-year-old subjects (n = 988) of the Prospective Study of the Vasculature in Uppsala Seniors (PIVUS). When these subjects were 70-, 75- and 80- years old, LV characteristics were measured by echocardiography, while fasting glucose, body mass index (BMI) and blood pressure were assessed with standard clinical techniques.
We found that p,p'-DDE levels were associated with increased fasting glucose, BMI, hypertension and LV mass in separate models adjusted for sex. Structural equation modeling revealed that the association between p,p'-DDE and LV mass was almost entirely mediated by BMI (70%), and also by hypertension (19%).
The obesogenic effect of p,p'-DDE is a major determinant responsible for the association of p,p'-DDE with LV mass.
OBJECTIVES: The objective of this study was to determine whether site-specific cancer incidence among farmers exposed to the insecticide lindane (g-hexachlorocyclohexane) while dipping sheep differs from that of the general population in Iceland. METHODS: Cohorts of 7882 men and 429 women, who, according to records on sheep dipping, were sheep owners, were followed from 1962 to 2003 in the Cancer Registry for cancer incidence. The observed number of cancers was compared with expected values, calculated on the basis of person-years of risk and cancer incidence in the general population of Iceland. RESULTS: For men the standardized incidence ratio (SIR) for all cancer sites was 0.79, with a 95% confidence interval (95% CI) of 0.76-0.83. For both the men and the women a significantly increased risk for lip cancer was found, with SIR of 1.50 (95% CI 1.08-2.04) and 9.09 (95% CI 1.02-32.82), respectively. The SIR for several cancer sites were lower than unity for both the men and women. Examples were cancers of the colon, rectum, pancreas, stomach, lungs, kidney, bladder, and brain and nervous system. CONCLUSIONS: The decreased risk of most cancers among these sheep farmers agrees with findings reported previously among farmers from other countries, as well as in Iceland. Cancer of the lip was the only cancer type in significant excess among both genders, and the stomach cancer rates were near unity, but, in previous studies on Icelandic farmers, an increase had been found for stomach cancer. The site-specific cancer incidence for sheep-dipping farmers did not differ substantially from that of the general population.
[Comparison of the urinary excretion of biomarkers of exposure to pyrethroids and pyrethrins between residents of urban and rural areas of the province of Quebec, Canada].
Residents of rural (agricultural) areas are often suspected of being exposed to higher levels of pesticides than residents of urban areas. However, only a limited number of studies have specifically evaluated the impact of the geographical area of residence on pyrethroid and pyrethrin exposure in the general population. This study aimed at comparing the levels of biomarkers of exposure between an urban and rural, adult and children, population of the Province of Quebec, Canada.
A total of 154 urban (Montreal) and 154 rural (Monteregie) participants provided a complete overnight timed-urine collection and filled a self-administered questionnaire. Urine samples were analyzed for pyrethroid and pyrethrin metabolites: cis- and trans-dichloro- and cis-dibromo- vinyldimethylcyclopropane carboxylic acids, phenoxy- and fluorophenoxy-benzoic acids and chrysanthemum dicarboxylic acid. Amounts of metabolites (pmol/12h par kilogram body weight) and their frequency of detection in the two populations were compared and interpreted with the help of the answers gathered by questionnaire.
Adults and children from the rural area tended to excrete higher levels of the main urinary metabolites, the cis- and trans-dichlorovinyldimethylcyclopropane carboxylic acids and the phenoxybenzoic acid, than those living in the urban area. When the adults and children were combined, this difference was statistically significant for the phenoxybenzoic acid (p=0.020), marginally significant for the trans-dichlorovinyldimethylcyclopropane carboxylic acid (p=0.053) and nonsignificant for the cis-dichlorovinyldimethylcyclopropane carboxylic acid (p=0.158). The chrysanthemum dicarboxylic acid, the fluorophenoxybenzoic acid and the dibromovinyldimethylcyclopropane carboxylic acid were detected in much lower proportion but, in the case of the fluorophenoxybenzoic acid, the relative frequency of detection was statistically significantly higher (p
The effect of synthetic pesticides and sulfur used in conventional and organically grown strawberry and soybean on Neozygites floridana, a natural enemy of spider mites.
The beneficial fungus Neozygites floridana kills the two-spotted spider mite Tetranychus urticae, which is a serious polyphagous plant pest worldwide. Outbreaks of spider mites in strawberry and soybean have been associated with pesticide applications. Pesticides may affect N. floridana and consequently the natural control of T. urticae. N. floridana is a fungus difficult to grow in artificial media, and for this reason, very few studies have been conducted with this fungus, especially regarding the impact of pesticides. The aim of this study was to conduct a laboratory experiment to evaluate the effect of pesticides used in strawberry and soybean crops on N. floridana.
Among the pesticides used in strawberry, the fungicides sulfur and cyprodinil + fludioxonil completely inhibited both the sporulation and conidial germination of N. floridana. The fungicide fluazinam affected N. floridana drastically. The application of the fungicide tebuconazole and the insecticides fenpropathrin and abamectin resulted in a less pronounced negative effect on N. floridana. Except for epoxiconazole and cyproconazole, all tested fungicides used in soybean resulted in a complete inhibition of N. floridana. Among the three insecticides used in soybean, lambda-cyhalothrin and deltamethrin resulted in a significant inhibition of N. floridana.
Arctic Alaskan Natives who maintain a traditional lifestyle have a disease profile that is significantly different from the general US population. There is concern that food sources containing environmental pollutants may contribute to this profile. In a preliminary study, umbilical cord blood was examined for the presence of several environmental contaminants. All cord blood samples analyzed thus far contain p,p'-DDE (1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene) with an average concentration of 0.33 microg/l. This study was undertaken to ascertain if this concentration of p,p'-DDE had detectable effects on immature cells in culture. NIH 3T3 (embryonic mouse fibroblast) and WS1 (human fetal fibroblast) cultures were exposed to media containing either 1 or 10 times the average cord blood concentration of p,p'-DDE. Initial experiments indicated that exposure to p,p'-DDE resulted in a decrease in the cell number of both cell types. Subsequent analysis revealed that the decrease in cell number was due to cell death in NIH 3T3 cells and to cell-cycle arrest in WS1 cells. Furthermore, p,p'-DDE decreased the long-term survival of NIH 3T3 but not WS1 cells. This study has demonstrated that p,p'-DDE, at relevant environmental concentrations, has significant effects on two immature mammalian cell types in culture. In addition, these results highlight the necessity for further studies to address the specific effects of p,p'-DDE on developing fetal systems.
Epidemiological studies have demonstrated an association between use of carbamate insecticides, including carbaryl, and increased incidence of allergic asthma in farmers. In this study the effect of oral carbaryl exposure on the development of allergic responses to house dust mite (HDM) was examined in female Brown Norway rats. Rats were gavaged for 2 weeks with 0, 2, 10, or 50 mg/kg/day of carbaryl. They were sensitized with a subcutaneous injection of HDM in aluminum hydroxide adjuvant 3 days after the beginning of carbaryl exposure and challenged with antigen via the trachea 1 day after the final carbaryl ingestion. Two days after challenge, antigen-specific cell proliferation in pulmonary lymph nodes was significantly higher in the 50 mg/kg group than in controls, while antigen-specific splenocyte proliferation was decreased in groups dosed with 2, 10, and 50 mg/kg carbaryl. Total protein and lymphocyte number in bronchoalveolar lavage (BAL) fluid were also increased in the 50 mg/kg group. By 7 days after challenge, immune-mediated pulmonary inflammation (eosinophils), antigen-specific immunoglobulin (Ig) E level in serum, and antigen-specific IgE and IgA levels in BAL fluid were significantly elevated in the 50 mg/kg group. No apparent change was observed for lactate dehydrogenase and eosinophil peroxidase in BAL fluid, while the number of BAL macrophages were decreased in groups dosed with 10 and 50 mg/kg carbaryl. The results suggest that carbaryl may cause systemic immune suppression, while enhancing pulmonary allergic responses to house dust mite antigen.
Centre d'Etudes Biologiques de Chizé (CEBC), UMR 7372 - CNRS & Université de la, Rochelle, 79360 Villiers-en-Bois, France. Electronic address: blevin.pierre@gmail.com.
Telomeres are DNA-protein complexes located at the end of chromosomes, which play an important role in maintaining the genomic integrity. Telomeres shorten at each cell division and previous studies have shown that telomere length is related to health and lifespan and can be affected by a wide range of environmental factors. Among them, some persistent organic pollutants (POPs) have the potential to damage DNA. However, the effect of POPs on telomeres is poorly known for wildlife. Here, we investigated the relationships between some legacy POPs (organochlorine pesticides and polychlorobiphenyls) and telomere length in breeding adult black-legged kittiwakes (Rissa tridactyla), an arctic seabird species. Our results show that among legacy POPs, only blood concentration of oxychlordane, the major metabolite of chlordane mixture, is associated with shorter telomere length in females but not in males. This suggests that female kittiwakes could be more sensitive to oxychlordane, potentially explaining the previously reported lower survival rate in most oxychlordane-contaminated kittiwakes from the same population. This study is the first to report a significant and negative relationship between POPs and telomere length in a free-living bird and highlights sex-related susceptibility to banned pesticides.