Louise N. Mehler

Acute Pesticide Poisoning Among Agricultural Workers in the United States, 1998-2005

BACKGROUND Approximately 75% of pesticide usage in the United States occurs in agriculture. As such, agricultural workers are at greater risk of pesticide exposure than non-agricultural workers. However, the magnitude, characteristics and trend of acute pesticide poisoning among agricultural workers are unknown. METHODS We identified acute pesticide poisoning cases in agricultural workers between the ages of 15 and 64 years that occurred from 1998 to 2005. The California Department of Pesticide Regulation and the SENSOR-Pesticides program provided the cases. Acute occupational pesticide poisoning incidence rates (IR) for those employed in agriculture were calculated, as were incidence rate ratios (IRR) among agricultural workers relative to non-agricultural workers. RESULTS Of the 3,271 cases included in the analysis, 2,334 (71%) were employed as farmworkers. The remaining cases were employed as processing/packing plant workers (12%), farmers (3%), and other miscellaneous agricultural workers (19%). The majority of cases had low severity illness (N = 2,848, 87%), while 402 (12%) were of medium severity and 20 (0.6%) were of high severity. One case was fatal. Rates of illness among various agricultural worker categories were highly variable but all, except farmers, showed risk for agricultural workers greater than risk for non-agricultural workers by an order of magnitude or more. Also, the rate among female agricultural workers was almost twofold higher compared to males. CONCLUSION The findings from this study suggest that acute pesticide poisoning in the agricultural industry continues to be an important problem. These findings reinforce the need for heightened efforts to better protect farmworkers from pesticide exposure.

Acute Pesticide Illnesses Associated with Off-Target Pesticide Drift from Agricultural Applications: 11 States, 1998–2006

Background: Pesticides are widely used in agriculture, and off-target pesticide drift exposes workers and the public to harmful chemicals. Objective: We estimated the incidence of acute illnesses from pesticide drift from outdoor agricultural applications and characterized drift exposure and illnesses. Methods: Data were obtained from the National Institute for Occupational Safety and Health’s Sentinel Event Notification System for Occupational Risks–Pesticides program and the California Department of Pesticide Regulation. Drift included off-target movement of pesticide spray, volatiles, and contaminated dust. Acute illness cases were characterized by demographics, pesticide and application variables, health effects, and contributing factors. Results: From 1998 through 2006, we identified 2,945 cases associated with agricultural pesticide drift from 11 states. Our findings indicate that 47% were exposed at work, 92% experienced low-severity illness, and 14% were children (< 15 years). The annual incidence ranged from 1.39 to 5.32 per million persons over the 9-year period. The overall incidence (in million person-years) was 114.3 for agricultural workers, 0.79 for other workers, 1.56 for nonoccupational cases, and 42.2 for residents in five agriculture-intensive counties in California. Soil applications with fumigants were responsible for the largest percentage (45%) of cases. Aerial applications accounted for 24% of cases. Common factors contributing to drift cases included weather conditions, improper seal of the fumigation site, and applicator carelessness near nontarget areas. Conclusions: Agricultural workers and residents in agricultural regions had the highest rate of pesticide poisoning from drift exposure, and soil fumigations were a major hazard, causing large drift incidents. Our findings highlight areas where interventions to reduce off-target drift could be focused.

Surveillance of Pesticide-Related Illness and Injury in Humans

Publisher Summary This chapter describes state-based, national, and international surveillance systems for pesticide-related illness and injury. Surveillance systems are the network of individuals and activities that engage in the process of surveillance. Pesticide poisoning among humans generally occurs either because of lack of compliance with existing pesticide regulations or because existing pesticide regulations are insufficient. The first cause involves cases that are preventable by following the precautionary measures specified on product labels and in governmental pesticide regulations. The second cause arises despite compliance with label instructions and regulatory measures and therefore requires interventions aimed at changing pesticide use practices and/or modifying regulatory measures. The focus of this chapter is on surveillance systems that operate in the United States (both state based and national); however, some information is provided on international surveillance efforts. Also described are some of the tools of surveillance, such as regulations that facilitate surveillance, efforts made to standardize case definitions and variables, and guidelines for evaluating surveillance systems. A comprehensive national surveillance system for acute pesticide-related illness and injury does not currently exist. Through standardization and information sharing across surveillance systems, a national comprehensive surveillance system may be attainable.Publisher Summary This chapter describes state-based, national, and international surveillance systems for pesticide-related illness and injury. Surveillance systems are the network of individuals and activities that engage in the process of surveillance. Pesticide poisoning among humans generally occurs either because of lack of compliance with existing pesticide regulations or because existing pesticide regulations are insufficient. The first cause involves cases that are preventable by following the precautionary measures specified on product labels and in governmental pesticide regulations. The second cause arises despite compliance with label instructions and regulatory measures and therefore requires interventions aimed at changing pesticide use practices and/or modifying regulatory measures. The focus of this chapter is on surveillance systems that operate in the United States (both state based and national); however, some information is provided on international surveillance efforts. Also described are some of the tools of surveillance, such as regulations that facilitate surveillance, efforts made to standardize case definitions and variables, and guidelines for evaluating surveillance systems. A comprehensive national surveillance system for acute pesticide-related illness and injury does not currently exist. Through standardization and information sharing across surveillance systems, a national comprehensive surveillance system may be attainable.

Acute Pesticide-Related Illnesses Among Working Youths, 1988-1999

OBJECTIVES The goal of this study was to describe acute occupational pesticide-related illnesses among youths and to provide prevention recommendations. METHODS Survey data from 8 states and from poison control center data were analyzed. Illness incidence rates and incidence rate ratios were calculated. RESULTS A total of 531 youths were identified with acute occupational pesticide-related illnesses. Insecticides were responsible for most of these illnesses (68%), most of which were of minor severity (79%). The average annual incidence rate among youths aged 15 to 17 years was 20.4 per billion hours worked, and the incidence rate ratio among youths vs adults was 1.71 (95% confidence interval = 1.53, 1.91). CONCLUSIONS The present findings suggest the need for greater efforts to prevent acute occupational pesticide-related illnesses among adolescents.

Acute illnesses associated with exposure to fipronil—surveillance data from 11 states in the United States, 2001–2007

Introduction. Fipronil is a broad-spectrum phenylpyrazole insecticide widely used to control residential pests and is also commonly used for flea and tick treatment on pets. It is a relatively new insecticide and few human toxicity data exist on fipronil. Objective. This paper describes the magnitude and characteristics of acute illnesses associated with fipronil exposure. Methods. Illness cases associated with exposure to fipronil-containing products from 2001 to 2007 were identified from the Sentinel Event Notification System for Occupational Risks (SENSOR)-Pesticides Program and the California Department of Pesticide Regulation. Results. A total of 103 cases were identified in 11 states. Annual case counts increased from 5 in 2001 to 30 in 2007. Of the cases, 55% were female, the median age was 37 years, and 11% were <15 years old. The majority (76%) had exposure in a private residence, 37% involved the use of pet-care products, and 26% had work-related exposures. Most cases (89%) had mild, temporary health effects. Neurological symptoms (50%) such as headache, dizziness, and paresthesia were the most common, followed by ocular (44%), gastrointestinal (28%), respiratory (27%), and dermal (21%) symptoms/signs. Exposures usually occurred from inadvertent spray/splash/spill of products or inadequate ventilation of the treated area before re‐entry. Conclusions. Our findings indicate that exposure to fipronil can pose a risk for mild, temporary health effects in various body systems. Precautionary actions should be reinforced to prevent fipronil exposure to product users.

Gender differences in acute pesticide-related illnesses and injuries among farmworkers in the United States, 1998–2007†

BACKGROUND Farmworkers have a high risk for acute pesticide-related illness and injury, and the rate among female farmworkers is approximately twice as high as that among males. Surveillance data were used to identify reasons for this gender difference. METHODS We identified acute pesticide-related illness and injury cases among farmworkers from the Sentinel Event Notification System for Occupational Risks (SENSOR)-Pesticides Program and the California Department of Pesticide Regulation. Gender-specific associations with acute pesticide-related illness and injury were assessed using chi-square tests. National Agricultural Workers Survey data were also examined. RESULTS The over-representation of females among farmworker illness and injury cases was confined to females who did not handle pesticides (non-handlers). Female non-handler farmworkers who were affected were more likely to be working on fruit and nut crops, to be exposed to off-target pesticide drift, and to be exposed to fungicides and fumigants compared to males. CONCLUSIONS Although there is an increased risk for acute pesticide-related illness and injury among female farmworkers, the absolute number of farmworkers with acute pesticide-related illness and injury is far higher among males than females. Furthermore, farmworkers have little or no control over many of the identified contributing factors that led to illness and injury. Stringent enforcement of existing regulations and enhanced regulatory efforts to protect against off-target drift exposures may have the highest impact in reducing acute pesticide-related illness and injury among farmworkers.

California Surveillance for Pesticide-Related Illness and Injury: Coverage, Bias, and Limitations

Abstract The California Pesticide Illness Surveillance Program (PISP) is a major resource for pesticide illness epidemiology. This work attempts to improve characterization of pesticide illness in California, evaluate case ascertainment of the PISP and identify PISPs limitations and biases for studying the incidence and epidemiology of pesticide-related illness. Abstractors collected standardized information from 1994–1996 PISP files, poison control logs, hospital records, and death certificates. Linkage produced a merged file of all records that documented consideration of pesticide exposure as a cause of ill health. We identified 23 deaths and estimated 1,310 hospitalizations attributable to pesticide exposure, corresponding to 0.024 fatalities and 1.38 hospitalizations (95% confidence interval [CI] = 1.01–1.74) per 100,000 California population person-years. Most intoxications followed domestic exposures and were not reported to the surveillance program, which identified primarily occupational exposures. Excluding groups of five or more, we estimated 16% ascertainment (CI = 0.05–0.27) for non-agricultural occupational cases. Agricultural connections increased the probability of ascertainment to about 50%, cultural and economic barriers notwithstanding. Surveillance records existed for all identified episodes in which five or more people were exposed. California pesticide surveillance data appear complete for mass exposures, and adequate to characterize agricultural and occupational exposures. Work is needed to explore domestic exposures and occurrences beyond the reach of the health care system.

Acute pesticide poisoning in the U.S. retail industry, 1998-2004.

Objective. This study was conducted to describe the national magnitude and characteristics of acute pesticide poisoning among workers and customers in retail establishments. Methods. Analyses included retail employees 15–64 years of age and customers with acute pesticide poisoning identified from the Sentinel Event Notification System for Occupational Risks-Pesticides (SENSOR-Pesticides) and California Department of Pesticide Regulation from 1998 to 2004. Pesticide poisoning incidence rates and incidence rate ratios (IRR) were calculated. Results. A total of 325 cases of acute pesticide poisoning were identified. Of these cases, 287 (88%) were retail employees and 38 (12%) were customers. Overall, retail employees had a significantly lower acute pesticide poisoning incidence rate compared with non-agricultural, non-retail employees (IRR=0.53; 95% confidence interval 0.47, 0.59). However, significantly elevated pesticide poisoning incidence rates were observed for four retail occupations (janitors, stock handlers/baggers, bakery/deli clerks, and shipping/receiving handlers). In addition, workers employed in two retail industry sectors (farm supply stores and hardware stores) had significantly elevated acute pesticide poisoning incidence rates. Incidence rates among the retail employees demonstrated a quadratic trend, monotonically decreasing from 1998 to 2000 and monotonically increasing from 2000 to 2003. The rates appear to have leveled off in 2003 and 2004. Conclusions. Preventive measures to decrease acute pesticide poisoning incidence in the retail sector include adoption of unbreakable and tear-resistant container requirements, increased utilization of integrated pest management strategies, and advisement to store managers, employees, and customers about poisoning prevention.

Community Exposure Following a Drip-Application of Chloropicrin

ABSTRACT Objectives. To evaluate illnesses resulting from community exposure to chloropicrin on October 5, 2005, in the agricultural community of Salinas, California. Methods. A cross-sectional interview survey was conducted of 142 households downwind from the application site in neighborhoods that were sources of emergency calls. A total of 439 residents of the 142 households in affected neighborhoods and 1 emergency responder were interviewed. The authors assessed exposure to chloropicrin resulting from the application using a public domain air pollution dispersion model, the Industrial Source Complex 3 (ISC3). Results. A total of 440 subjects were represented in the interviews, including 324 (73.6%) who reported symptoms possibly or probably related to chloropicrin exposure. Ocular symptoms were present in 302 (93.2%) of the symptomatic cases. Nonocular (usually systemic or respiratory) symptoms occurred in 170 cases (52.5%), but occurred significantly more frequently in residents who lived within 0.46 miles of the application site. Air-modeling showed a plume of chloropicrin in the affected neighborhoods, with estimated 1-h TWA (time-weighted average) air concentrations between 0.15 and 0.025 ppm. Conclusions. Ocular, respiratory, and systemic symptoms on the evening of October 5, 2005, corresponded to a plume of chloropicrin, with estimated concentrations as high as 0.15 ppm, in the community of Salinas, California. Cases occurred between 0.36 and 2.89 miles from the application site. Use of irritant agricultural fumigants near residential neighborhoods can produce a risk of illness for distances more than 2 miles from the site of application. Air modeling is useful for evaluating the relationship between possible exposures and community symptoms.

Inhalation of phosphine gas following a fire associated with fumigation of processed pistachio nuts

ABSTRACT On December 10, 2009, a fumigation stack containing aluminum phosphide became soaked with rain water and caught fire at a pistachio processing plant in Kern County, California. Untrained plant personnel responding to the fire had exposure to pyrolysis by-products, particulates, and extinguisher ingredients. Ten workers taken for medical evaluation had respiratory and nonspecific systemic symptoms consistent with exposure to phosphine gas. Six of the 10 workers had respiratory distress, indicated by chest pain, shortness of breath, elevated respiratory rate, or decreased oxygen saturation. Recommendations are made for the management of similar illnesses and prevention of similar exposures.