Dietary exposures to selected metals and pesticides.

Average daily dietary exposures to 11 contaminants were estimated for approximately 120,000 U.S. adults by combining data on annual diet, as measured by a food frequency questionnaire, with contaminant residue data for table-ready foods that were collected as part of the annual U.S. Food and Drug Administration Total Diet Study. The contaminants included in the analysis were four heavy metals (arsenic, cadmium, lead, mercury), three organophosphate pesticides (chlorpyrifos, diazinon, malathion), and four organochlorine pesticides (dieldrin, p,p'-DDE, lindane, heptachlor epoxide). Dietary exposures to these contaminants were highly variable among individuals, spanning two to three orders of magnitude. Intraindividual exposures to the metals, organophosphates, and organochlorines were estimated to be strongly correlated; Pearson's correlation coefficients ranged from 0.28 for lindane:dieldrin to 0.84 for lead:mercury. For some of the compounds (e.g., arsenic and dieldrin), a substantial fraction of the population was estimated to have dietary intakes in excess of health-based standards established by the EPA. Before use for risk assessment or epidemiologic purposes, however, the validity of the exposure estimates must be evaluated by comparison with biological indicators of chronic exposure. Because of their low detection rate in table-ready foods, the estimated distributions of exposures for dieldrin, p,p'-DDE, heptachlor epoxide, lindane, diazinon, and chlorpyrifos were found to be sensitive to assumed values for nondetect samples. Reliable estimates of the population distribution of dietary exposures to most other contaminants cannot be made currently, due to their low rate of detection in table-ready foods. Monitoring programs that use more sensitive study designs and population-based assessments for other subpopulations should be a priority for future research.     

Human exposures to pesticides in the United States

Pesticides are used in most homes, businesses, and farms to control a variety of pests, including insects, weeds, fungi, rodents, and even microbial organisms. Inappropriate use of pesticides can lead to adverse effects to humans and the environment. This study provides updated information on the magnitude of adverse pesticide exposures in the United States. Data on pesticide exposure were obtained from calls to poison control centers (PCCs) reported by the American Association of Poison Control Centers. Estimates of emergency department visits, hospitalizations, and health care costs were reported by the Agency for Healthcare Research and Quality (AHRQ), and deaths from pesticide poisonings reported by the Centers for Disease Control and Prevention (CDC) WONDER (Wide-ranging Online Data for Epidemiologic Research). An average of 23 deaths occur each year with pesticides as the underlying cause of death, most due to suicidal ingestions. An average of 130,136 calls to poison control centers were reported from 2006 to 2010, with an average of 20,116 cases (17.8%) treated in health care facilities annually. AHQR reported an annual average of 7385 emergency room visits during 2006 to 2008, and 1419 annual hospitalizations during 2005 to 2009. Excluding cost from lost work time, hospital physician fees, and pesticide-induced cancers, the annual national cost associated with pesticide exposures was estimated as nearly $200 million USD based on data from emergency department visits, hospitalizations, and for deaths. Pesticide exposures remain a significant public health issue. Health care providers, cooperative extension agents, and pesticide manufactures can help prevent exposures by increasing education of parents and workers, encourage use of less toxic agents, and encourage the practice of integrated pest management.     

Estimating exposures to indoor contaminants using residential dust

Residential dust has been used as a medium for assessing human exposures to a constellation of indoor contaminants including radionuclides, persistent organic pollutants, metals, allergens, and tobacco smoke. Here, we review and comment on investigations of household dust levels of particular analytes of health significance, namely polybrominated diphenyl ethers, polychlorinated biphenyls, and polycyclic aromatic hydrocarbons. In doing so, we not only describe methods for collecting and analyzing residential dust, but also describe global patterns in dust levels. Aside from geographic location, we discuss several potential determinants for dust levels of these contaminants. We also review previous estimates of the contribution of dust to overall intake of these three chemical classes and show how residential-dust measurements could be useful in either augmenting or replacing questionnaire-based assessment of human exposures in epidemiological studies. We conclude our review with a discussion of the current gaps in knowledge of worldwide dust levels and suggestions for how residential-dust measurements could be used to describe human exposures to chemicals in developing countries.     

Wilms' tumor and exposures to residential and occupational hazardous chemicals

This case-control study examines the association between residential and occupational exposures to hazardous chemicals and the risk of Wilms' tumor. The study included 303 cases recruited from six state cancer registries, who were diagnosed between January 1, 1992 and December 31, 1995. A total of 575 controls selected through random digit dialing were frequency matched to the cases. A standard questionnaire was administered to participants during a telephone interview. Parental residential addresses and locations of US Environmental Protection Agency National Priority List (NPL) sites were geocoded and analyzed, along with occupational exposure information. There were no cases of Wilms' tumor found in individuals living within one-half mile distance of a hazardous waste site. However, elevated odds ratios were found for using hairdressing chemicals, motor oil, paint, paint stripper, and pesticides during the pregnancy term and during the 2-year period prior to birth. The findings do not support the hypothesis that Wilms' tumor is associated with residing near an NPL site.     

Acute hazards to young children from residential pesticide exposures

OBJECTIVES: This study assessed acute hazards to young children from pesticides toxic enough to require child-resistant packaging. METHODS: The names of pesticides meeting acute toxicity criteria were ascertained from the Environmental Protection Agency. Poison Control Center reports identified children younger than 6 years who were exposed to these pesticides. Toxicity category, medical outcome, sex, and age were examined. RESULTS: A higher proportion of children with exposure to the more toxic products had serious medical outcomes. Children 2 years and younger were the predominant age group exposed. CONCLUSIONS: Protective measures--substituting less lethal pesticides, reducing the concentration of the active ingredients, and improving packaging and storage--are recommended.     

CAREX Nicaragua and Panama: Worker exposures to carcinogenic substances and pesticides

This study provides data on numbers of workers exposed at work to selected carcinogens and pesticides in Nicaragua (35 substances) and Panama (31), based on a modification of the CAREX data system. Population censuses provided industry- and sex-specific workforce numbers. The activity- and sex-specific proportions of exposed workers were estimated by experts from governmental agencies, workers' organizations, and employers' representatives. Finally, the numbers of those occupied in each activity/sex category were multiplied by the proportions of those exposed in the same categories, yielding numbers of those exposed in these categories for each agent. The study revealed high proportions (> 9%) of occupationally exposed workers in both countries for solar radiation and diesel engine emissions; environmental tobacco smoke in Panama; and some pesticides in Nicaragua. A high proportion of exposed was found for men for lead (12%), silica dust (10%), and hexavalent chromium (10%) in Panama.     

Hypersensitivity pneumonitis from ordinary residential exposures.

A previously healthy woman developed hypersensitivity pneumonitis of such severity that she required chronic systemic corticosteroid therapy for symptom control. Detailed investigation of her workplace and home environments revealed fungi in her typical suburban home, to which she had specific serum precipitating antibodies. Efforts to remove mold from the home were unsuccessful in relieving symptoms, and moving to another residence was the only intervention that allowed her to be withdrawn from corticosteroid therapy. Hypersensitivity pneumonitis is commonly associated with occupational or avocational exposures, such as moldy hay in farmers or bird antigen in bird breeders. We propose that hypersensitivity pneumonitis may occur in North America, as it does in Japan, from domestic exposures alone.     

Investigation of associations between exposures to pesticides and testosterone levels in Thai farmers

We conducted a cross-sectional study to assess the relationship between pesticide exposures and testosterone levels in 133 male Thai farmers. Urine and serum samples were collected concurrently from participants. Urine was analyzed for levels of specific and nonspecific metabolites of organophosphates (OPs), pyrethroids, select herbicides, and fungicides. Serum was analyzed for total and free testosterone. Linear regression analyses revealed significant negative relationships between total testosterone and the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) after controlling for covariates (eg, age, BMI, smoking status). Positive significant associations were found between some OP pesticides and total testosterone. Due to the small sample size and the observational nature of the study, future investigation is needed to confirm our results and to elucidate the biological mechanisms.     

Risk of stillbirth from occupational and residential exposures.

OBJECTIVES: To analyse the risk of stillbirth from 12 residential and occupational maternal exposures during pregnancy. METHODS: Stillbirths and neonatal deaths in 1984 within 24 hours of birth from 10 California counties were identified from death certificates. Controls were randomly selected from live births born in 1984 and frequency matched to cases by maternal age and county. Data sources included vital statistics and a self-administered postal questionnaire. Logistic regression and proportional hazards modelling were performed; the proportional hazards considered the truncated opportunity for exposure among cases. Special focus was given to two cause of deaths groups: congenital anomalies (12% of deaths) and complications of the placenta, cord, and membranes (37% of deaths). RESULTS: Occupational exposure to pesticides during the first two months of gestation was positively associated with stillbirths due to congenital anomalies (odds ratio (OR) 2.4, 95% confidence interval (95% CI) 1.0 to 5.9), and during the first and second trimesters with stillbirths due to all causes of death (risk ratios (RR) 1.3-1.4, 95% CI 1.0 to 1.7) and stillbirths due to complications of the placenta, cord, and membranes (RR 1.6-1.7, 95% CI 1.1 to 2.3). Occupational exposure to video display terminals in the third trimester was found to have a modest inverse association with stillbirths (RR 0.7, 95% CI 0.6, 0.9). Home pesticide exposure was positively associated with stillbirths due to congenital anomalies (OR 1.7, 95% CI 1.0 to 2.9). CONCLUSIONS: Occupational exposure to pesticides, especially during early pregnancy, had a clear positive association with stillbirths regardless of cause of death. Methodologically, this study of stillbirths is unique in its analysis of specific causes of death and use of time specific exposure windows.     

Non-occupational exposures to pesticides for residents of two U.S. cities

The Non-Occupational Pesticide Exposure Study, funded by the U.S. Environmental Protection Agency, was designed to assess total human exposures to 32 pesticides and pesticide degradation products in the non-occupational environment; however, the study focused primarily on inhalation exposures. Two sites—Jacksonville, Florida (USA) and Springfield/Chicopee, Massachusetts (USA)—were studied during three seasons: Summer 1986 (Jacksonville only), Spring 1987, and Winter 1988. Probability samples of 49 to 72 persons participated in individual site/seasons. The primary environmental monitoring consisted of 24-hr indoor, personal, and outdoor air samples analyzed by gas chromtography/mass spectrometry and gas chromatography/electron capture detection. Indoor and personal air concentrations tended to be higher in Jacksonville than in Springfield/Chicopee. Concentrations tended to be highest in summer, lower in spring, and lowest in winter. Indoor and personal air concentrations were generally comparable and were usually much higher than outdoor air concentrations. Inhalation exposure exceeded dietary exposure for cyclodiene termiticides and for pesticides used mainly in the home. Dietary exposures were greater for many of the other pesticides. Inhalation risks were uncertain for termiticides (depending on rates of degradation) but were negligible for other pesticides. The data were insufficient to support risk assessments for food, dermal contact, or house dust exposures.     

Community exposures to airborne agricultural pesticides in California: ranking of inhalation risks

We assessed inhalation risks to California communities from airborne agricultural pesticides by probability distribution analysis using ambient air data provided by the California Air Resources Board and the California Department of Pesticide Regulation. The pesticides evaluated include chloropicrin, chlorothalonil, chlorpyrifos, S,S,S-tributyl phosphorotrithioate, diazinon, 1,3-dichloropropene, dichlorvos (naled breakdown product), endosulfan, eptam, methidathion, methyl bromide, methyl isothiocyanate (MITC; metam sodium breakdown product), molinate, propargite, and simazine. Risks were estimated for the median and 75th and 95th percentiles of probability (50, 25, and 5% of the exposed populations). Exposure estimates greater than or equal to noncancer reference values occurred for 50% of the exposed populations (adults and children) for MITC subchronic and chronic exposures, methyl bromide subchronic exposures (year 2000 monitoring), and 1,3-dichloropropene subchronic exposures (1990 monitoring). Short-term chlorpyrifos exposure estimates exceeded the acute reference value for 50% of children (not adults) in the exposed population. Noncancer risks were uniformly higher for children due to a proportionately greater inhalation rate-to-body weight ratio compared to adults and other factors. Target health effects of potential concern for these exposures include neurologic effects (methyl bromide and chlorpyrifos) and respiratory effects (1,3-dichloropropene and MITC). The lowest noncancer risks occurred for simazine and chlorothalonil. Lifetime cancer risks of one-in-a-million or greater were estimated for 50% of the exposed population for 1,3-dichloropropene (1990 monitoring) and 25% of the exposed populations for methidathion and molinate. Pesticide vapor pressure was found to be a better predictor of inhalation risk compared to other methods of ranking pesticides as potential toxic air contaminants.     

Farmers' perceptions of pesticides,and resultant health problems from exposures

As part of an evaluation study of the impacts of the Indonesian integrated pest management (IPM) Farmer Field Schools on farmers' health, focus group discussions were conducted with rice farmers who grew shallots in rotation. Farmers who had previously participated in IPM rice field schools and who were at the time participating in IPM shallot field schools were compared with farmers who had had no experience with IPM methods. The study found that farmers' knowledge concerning the health dangers of pesticides is not sufficient to change their behaviors. Their overriding concern is crop damage that leads to economic loss, not health. IPM field-school training offers farmers a viable alternative by concretely demonstrating the health, agricultural, environmental, and economic advantages of eliminating unnecessary pesticide use. If public health professionals aim to change behaviors through interventions, they must employ appropriate methods, meet the community's priorities and values, and offer feasible alternatives.     

Traffic-related exposures,constrained restoration,and health in the residential context

Traffic-related exposures may undermine the restorative character of the home, and this may in turn undermine health and residential satisfaction. We addressed this possibility with data for adults residing in a large valley near Innsbruck, Austria (N=572). We joined objective measures of traffic-related sound and air pollutants with reports from door-to-door surveys concerning perceived disturbance from traffic-related exposures, restorative qualities of the living environment, self-perceived health and residential satisfaction. We analyzed these data with successive tests of nested structural equation models, with and without the restorative quality variables. The results suggest that the negative impact of traffic-related exposures on self-perceived health and satisfaction with the living environment involves the constraint of restorative qualities of the living environment, over and above the share traditionally attributed to such exposures viewed as stressors. We discuss theoretical and practical implications of the distinction between environmental stressors and constraints on restoration.     

Use of point-of-sale data to track usage patterns of residential pesticides: methodology development

Background  

Residential-use pesticides have been shown to be a major source of pesticide exposure to people in the United States. However, little is understood about the exposures to household pesticides and the resultant health effects. One reason that little is known about home-use pesticide exposure is the lack of comprehensive data on exposures to pesticides in the home. One method to help ascertain the amount of pesticides present in the home is use of point-of-sale data collected from marketing companies that track product sales to obtain the volume of pesticides sold for home-use. This provides a measure of volume of home-use pesticide.     

Occupational exposures to metals, solvents and pesticides: recent evidence on male reproductive effects and biological markers

This review is based primarily on the recent epidemiological studies conducted in occupational settings in order to explore the relationship between exposures to chemical agents and the possible effects on male reproductive function. The paper examines evidence of the effects of metals, solvents, pesticides and dioxin. The effects considered are primarily the possible alterations of sperm quality and reduction of fertility. Many studies have identified small groups of workers with exposures to these agents, presenting some alteration in the spermatological or fertility profile, but the results are difficult to replicate in other settings with different individuals and different levels of exposure. From examination of the concentrations of environmental and occupational pollutants in the blood and in the seminal fluid of exposed individuals, it appears that, in general, the concentrations are much lower in the seminal fluid and in sperm cells, making this a less useful marker of exposure.     

Self-reported exposure to pesticides in residential settings and risk of breast cancer: a case-control study

Background  

Pesticides are widely used in households to control insects and weeds. Several studies, over the past decades, have examined the possible relationship of serum concentration of organochlorine pesticides and the development of breast cancer. However, little data exists regarding an association between self-reported, residential exposure to pesticides and breast cancer risk. We, therefore, present a case-control study examining self-reported exposure to household pesticides with regard to associated risk of breast cancer.     

Adult glioma in relation to residential power frequency electromagnetic field exposures in the San Francisco Bay area.

In a population-based study, we examined residential power frequency electromagnetic field exposures for 492 adults newly diagnosed with histologically confirmed glioma between August 1, 1991 and April 30, 1994, in the San Francisco Bay area and 462 controls, obtained through random-digit dialing frequency, matched to cases for age, gender, and race. Residential exposure assessment consisted of spot measures with EMDEX (Enertech Consultants, Campbell, CA) meters and wire codes based on characterization and location of nearby power lines. We considered the index residence at the time of the case's diagnosis or the control's interview and all other California residences of each subject for 7 years before study entry. We obtained wire codes for eligible residences of 76% and for index residences of 99% of subjects. Using the Kaune-Savitz wire code classification, the relative risk for longest held residences coded as "high" compared with "low" was 0.9 [95% confidence interval (CI) = 0.7-1.3], while relative risk and 95% CIs for front door spot measures of 1.01-2 milligauss, 2.01-3 milligauss, and higher than 3 milligauss compared with < or =1 milligauss were 1.0 (0.7-1.4), 0.6 (0.3-1.1), and 1.7 (0.8-3.6). Adjustment for age, gender, race, and whether the subject owned the residence did not meaningfully alter these findings, nor did comparisons using index or highest coded residence. Because of potential exposure misclassification and the unknown pertinent exposure period, these data cannot provide strong support against, but clearly do not support an association between, adult glioma and residential power frequency electromagnetic field exposures.     

Rapid method for determining dermal exposures to pesticides by use of tape stripping and FTIR spectroscopy: a pilot study

Tape stripping is a common method for estimating dermal exposure to pesticides because it is relatively noninvasive and easy to use. A major disadvantage is that samples are usually analyzed with gas chromatography, a time-consuming method in terms of sample preparation. In this study, the authors evaluated the feasibility of using Fourier transform infrared spectroscopy (FTIR) to analyze tape stripped samples to provide near real-time dermal exposure estimates. Various exposure scenarios were evaluated, including a single chemical (i.e., chlorpyrifos, a commonly used pesticide) and a mixture of two chemicals (i.e., chlorpyrifos and captan); these were analyzed with or without the human stratum corneum in the samples. Infrared transparent tape was used for sample collection; samples were analyzed using a FTIR spectrometer in the transmittance mode. The partial least squares algorithm was applied to quantify the spectra and the respective R(2) values for calibration, and test samples were larger than 0.99 and 0.90. The percent divergence of this approach was mostly below 10%, except for several low loading samples. The ANOVA test showed that the stratum corneum's influence on the percent divergence was not significant. Although all the samples evaluated in this study were collected from the same human subject, advantages and feasibility of the stripping-FTIR approach were demonstrated.