Acute organophosphate (OP) pesticide exposure is associated with adverse central nervous system (CNS) outcomes, however, little is known about the neurotoxicity of chronic exposures that do not result in acute poisoning. To examine associations between long-term pesticide use and CNS function, neurobehavioral (NB) tests were administered to licensed pesticide applicators enrolled in the Agricultural Health Study (AHS) in Iowa and North Carolina. Between 2006 and 2008, 701 male participants completed nine NB tests to assess memory, motor speed and coordination, sustained attention, verbal learning and visual scanning and processing. Data on ever-use and lifetime days of use of 16 OP pesticides were obtained from AHS interviews conducted before testing between 1993 and 2007 and during the NB visit. The mean age of participants was 61 years (SD = 12). Associations between pesticide use and NB test performance were estimated with linear regression controlling for age and outcome-specific covariates. NB test performance was associated with lifetime days of use of some pesticides. Ethoprop was significantly associated with reduced performance on a test of motor speed and visual scanning. Malathion was significantly associated with poor performance on a test of visual scanning and processing. Conversely, we observed significantly better test performance for five OP pesticides. Specifically, chlorpyrifos, coumaphos, parathion, phorate, and tetrachlorvinphos were associated with better verbal learning and memory; coumaphos was associated with better performance on a test of motor speed and visual scanning; and parathion was associated with better performance on a test of sustained attention. Several associations varied by state. Overall, our results do not provide strong evidence that long-term OP pesticide use is associated with adverse CNS-associated NB test performance among this older sample of pesticide applicators. Potential reasons for these mostly null associations include a true absence of effect as well as possible selective participation by healthier applicators.

Background: Evidence is limited that long-term human exposure to organophosphate (OP) pesticides, without poisoning, is associated with adverse peripheral nervous system (PNS) function.Objective: We investigated associations between OP pesticide use and PNS function by administering PNS tests to 701 male pesticide applicators in the Agricultural Health Study (AHS).Methods: Participants completed a neurological physical examination (NPx) and electrophysiological tests as well as tests of hand strength, sway speed, and vibrotactile threshold. Self-reported information on lifetime use of 16 OP pesticides was obtained from AHS interviews and a study questionnaire. Associations between pesticide use and measures of PNS function were estimated with linear and logistic regression controlling for age and outcome-specific covariates.Results: Significantly increased odds ratios (ORs) were observed for associations between ever use of 10 of the 16 OP pesticides and one or more of six NPx outcomes. Most notably, abnormal toe proprioception was significantly associated with ever use of 6 OP pesticides, with ORs ranging from 2.03 to 3.06; monotonic increases in strength of association with increasing use was observed for 3 of the 6 pesticides. Mostly null associations were observed between OP pesticide use and electrophysiological tests, hand strength, sway speed, and vibrotactile threshold.Conclusions: This study provides some evidence that long-term exposure to OP pesticides is associated with signs of impaired PNS function among pesticide applicators.

Purpose While acute pesticide poisoning can be associated with persistent adverse central nervous system (CNS) effects, little is known about the effect of episodic and unusually high pesticide exposure events (HPEEs) that typically do not result in acute poisoning. The objective of this investigation was to examine the association between HPEEs and CNS function among licensed pesticide applicators enrolled in the Agricultural Health Study (AHS). Methods In 2006–2008, 693 male participants, with no history of a physician-diagnosed pesticide poisoning, completed nine neurobehavioral tests to assess memory, motor speed, sustained attention, verbal learning, and visual scanning and processing. Information on HPEEs and pesticide poisonings was obtained from previous AHS interviews. Associations between HPEEs and neurobehavioral outcomes were estimated with linear regression controlling for age and outcome-specific covariates. Results A history of at least one HPEE was reported by 156 (23%) participants. Adverse associations were observed between HPEEs and two of the nine neurobehavioral tests. On a test of visual scanning and processing (Digit-Symbol), participants with HPEEs were 4.2 seconds slower (95% CI: −7.27, −1.11) than those without HPEEs, equivalent to the effect of 3.9 years of age in this population. On a test of visual scanning and motor speed (Sequences A), participants with HPEEs were 2.5 seconds slower (95% CI: −4.53, −0.41) than those without HPEEs, equivalent to the effect of 3.9 years of age. No significant associations were observed between HPEEs and the other neurobehavioral tests. Conclusions HPEEs may contribute to adverse CNS outcomes independent of diagnosed pesticide poisoning.

Background-Because of its recent identification, few multi-year epidemiologic studies of hMPV infection have been reported.Objective-We sought to retrospectively describe hMPV infections among patients evaluated by a large US Midwestern referral laboratory. Results-34 (2.6%) of 1294 specimens were hMPV positive. Among these, 21 (62%) were culture positive and available for genetic typing. A previously considered rare genotype of hMPV, B1, was the most common single genotype identified, comprising 9 (43%) of the 21 isolates. Multivariate logistic regression modeling identified patients aged 0.4-9 years (OR = 8.9; 95% CI = 2.0-38.5) and those under intensive care (OR = 3.2; 95% CI = 1.1-8.7) as more likely to have hMPV infection than their peers.Conclusion-In this large referral hospital viral assays more often had evidence of hMPV when they were collected from children receiving intensive care.

Purpose Although organic solvents are often used in agricultural operations, neurotoxic effects of solvent exposure have not been extensively studied among famers. The current analysis examined associations between questionnaire-based metrics of organic solvent exposure and depressive symptoms among farmers. Methods Results from 692 male Agricultural Health Study participants were analyzed. Solvent type and exposure duration were assessed by questionnaire. An “ever-use” variable and years of use categories were constructed for exposure to gasoline, paint/lacquer thinner, petroleum distillates, and any solvent. Depressive symptoms were ascertained with the Center for Epidemiologic Studies Depression Scale (CES-D); scores were analyzed separately as continuous (0-60) and dichotomous (<16 versus ≥16) variables. Multivariate linear and logistic regression models were used to estimate crude and adjusted associations between measures of solvent exposure and CES-D score. Results Forty-one percent of the sample reported some solvent exposure. The mean CES-D score was 6.5 (SD=6.4; median=5; range=0 – 44); 92% of the sample had a score below 16. After adjusting for covariates, statistically significant associations were observed between ever-use of any solvent, long duration of any solvent exposure, ever-use of gasoline, ever-use of petroleum distillates, and short duration of petroleum distillate exposure and continuous CES-D score (p<0.05). Although nearly all associations were positive, fewer statistically significant associations were observed between metrics of solvent exposure and the dichotomized CES-D variable. Conclusions Solvent exposures were associated with depressive symptoms among farmers. Efforts to limit exposure to organic solvents may reduce the risk of depressive symptoms among farmers.