Matthew Keifer

ISAAC‐based asthma and atopic symptoms among Ha Noi school children

Childhood asthma and atopy prevalence patterns in the developing world are only beginning to be defined. No such information exists for Vietnam. Estimates would assist in anticipating health service needs as well as add to the growing database on global patterns of atopy. To estimate the prevalence of atopic symptoms in school children in Ha Noi, Vietnam, a cross‐sectional survey was conducted of children aged 5‐ to 11‐years‐old in two schools using the parent self‐administered International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. The response rate was 66.4% (969 responses). The overall prevalence of selected symptoms were: ‘ever wheezed’ 24.9%, ‘wheezed in past 12 months’ 14.9%, ‘ever had asthma’ 12.1%, ‘doctor‐diagnosed asthma’ 13.9%, ‘ever experienced allergic rhinitis (AR) symptoms’ 34.9%, ‘AR‐conjunctivitis symptoms in past 12 months’ 10.7%, ‘ever had hay fever’ 7.8%, ‘doctor‐diagnosed hay fever’ 11.2%, ‘ever had eczema’ 3.3% and ‘doctor‐diagnosed eczema’ 3.2%. Kappa statistics demonstrated high within symptom category consistency for ‘ever had asthma/doctor‐diagnosed asthma’ (0.728) and ‘ever had eczema/doctor‐diagnosed eczema’ (0.906). Age and gender adjusted odds ratios (OR) were also consistently significant across wheeze and allergic rhinitis symptom categories [highest OR = 10.10 (95% CI 6.23–16.35) between allergic rhinoconjunctivitis and wheeze in past 12 months]. There is a high prevalence of ISAAC‐based symptoms in school children in Ha Noi, Vietnam, often above global averages. The high level of association between atopic symptoms suggests some degree of reliability and validity. Childhood atopy symptom prevalence in Vietnam is more similar to that in developed countries rather than developing countries.

Effects of Social, Economic, and Labor Policies on Occupational Health Disparities

BACKGROUND This article introduces some key labor, economic, and social policies that historically and currently impact occupational health disparities in the United States. METHODS We conducted a broad review of the peer-reviewed and gray literature on the effects of social, economic, and labor policies on occupational health disparities. RESULTS Many populations such as tipped workers, public employees, immigrant workers, and misclassified workers are not protected by current laws and policies, including workers compensation or Occupational Safety and Health Administration enforcement of standards. Local and state initiatives, such as living wage laws and community benefit agreements, as well as multiagency law enforcement contribute to reducing occupational health disparities. CONCLUSIONS There is a need to build coalitions and collaborations to command the resources necessary to identify, and then reduce and eliminate occupational disparities by establishing healthy, safe, and just work for all.

Blood acetylcholinesterase and butyrylcholinesterase as biomarkers of cholinesterase depression among pesticide handlers

Objective Agricultural pesticide handlers are at an elevated risk for overexposure to organophosphate (OP) pesticides, but symptoms can be difficult to recognise, making biomarkers invaluable for diagnosis. Occupational monitoring programmes for cholinesterase depression generally rely on measuring activity of either of the two common blood cholinesterases which serve as proxy measurements for nervous-system acetylcholinesterase activity: red blood cell acetylcholinesterase (AChE) and plasma butyrylcholinesterase (BChE). These biomarkers, however, may be affected differentially by some OPs and the relationship between them has not been well characterised. We aim to determine the association between blood AChE and BChE activity levels and assess whether they produce comparable classifications of clinical cholinesterase depression among OP pesticide handlers. Methods Using blood samples from 215 participants of the Washington State Cholinesterase Monitoring Program, we quantified changes in AChE and BChE activity from before and after exposure to OP pesticides and calculated Pearson correlation statistics for correlation of AChE and BChE changes in activity, as well as weighted κ statistics for agreement of classification of clinical cholinesterase depression based on AChE versus BChE measurements. Results AChE and BChE activity measurements are weakly negatively correlated in our study population. Reaching a clinical threshold for diagnosis of cholinesterase depression based on the AChE marker did not correlate with reaching clinical depression based on the BChE marker. Conclusions Both AChE and BChE should be measured in monitoring programmes because they may both give potentially important but disparate classifications of clinical cholinesterase depression.

Immigrant dairy workers' perceptions of health and safety on the farm in America's Heartland.

BACKGROUND Dairy farming is dangerous. Yearly, farms grow fewer and larger by employing immigrant workers, who have limited industrial agriculture experience and safety and health training. METHODS We examined results of five focus groups with 37 Hispanic, immigrant dairy workers. Analysis followed a grounded theory approach and employed ATLAS.ti. RESULTS Reported injury experience affirmed the hazardous nature of dairy. Some workers received appropriate worker compensation benefits, whereas others were instructed to deny work-relatedness. Some employers covered medical injury costs out-of-pocket, whereas others did not. Cows were a major injury source. Pressure to work and weather were noted as injury risk factors. Worker compensation was poorly understood, and immigration status and fear of deportation influenced injury and hazard reporting. CONCLUSION Injury management practices range from benevolent to threatening. Workers compensation is poorly understood and undocumented status is an occupational hazard. We underscore the need for further research and immigration policy change.

Determinants of Butyrylcholinesterase Inhibition Among Agricultural Pesticide Handlers in Washington State: An Update

OBJECTIVES Organophosphate (OP) and N-methyl-carbamate (CB) insecticides are used widely in agriculture to manage insect pests of economic importance. Agricultural workers are more likely to suffer exposure because of the widespread use of OP/CBs in agriculture, and pesticide-related illnesses among handlers may be more severe when compared to other farm workers. The goal of this study was to identify occupational and personal characteristics associated with butyrylcholinesterase (BuChE) inhibition in participants recruited from the Washington State Cholinesterase Monitoring Program from 2006 to 2011. METHODS We conducted a longitudinal study among agricultural pesticide handlers in Washington State during the OP/CB spray season (March-July) over a 6-year period (2006-2011). Linear mixed effects regression models were used to evaluate BuChE inhibition in relation to self-reported occupational and personal characteristics. RESULTS Relative to pre-season baseline levels, the mean decrease in BuChE activity during the OP/CB spray season over all years of the study period was 3.77% (P < 0.001). Greater BuChE inhibition was observed among handlers who reported using multiple OP/CBs (β = -2.70, P = 0.045), mixed or loaded OP/CBs (β = -3.97, P = 0.002), did not store personal protective equipment (PPE) in a locker at work (β = -3.4, P = 0.014), or did not wear chemical-resistant boots (β = -16.6, P < 0.001). DISCUSSION AND CONCLUSIONS The Washington State Cholinesterase Monitoring Program has provided a valuable opportunity to evaluate potential sources of OP/CB exposure among agricultural pesticide handlers. Several previously reported associations were confirmed in the current analysis, which included a larger number of pesticide handlers enrolled over a longer time period. The use of multiple OP/CBs and mixing/loading activities were significant risk factors, and the use of chemical-resistant boots and lockers for PPE storage were protective factors. Our findings point toward logical interventions to reduce exposure such as the implementation of engineering controls for mixing/loading activities, requirements for appropriate footwear, and the regular use of lockers for PPE storage.

Applying Learning Theory to Safety and Health Training for Hispanic Immigrant Dairy Workers

We designed a safety and health curriculum for dairy immigrant workers aiming to increase knowledge, encourage safe behavior, and reduce worker communication inequalities to prevent occupational injury and diseases. The design is largely based on the Taxonomy of Significant Learning and incorporated behavioral and adult learning theories and principles of occupational hazard control. Trainings were implemented with 836 Spanish-speaking workers from 67 farms in Wisconsin. Sixty-seven percent of workers reported never being trained before in dairy safety, 65% of these worked in dairy for 5 or fewers years, and 26% of workers reported being ever injured while working on dairy. Quantitative and qualitative evaluation of the trainings suggest that our curriculum successfully increased worker knowledge and promoted contemplation of safe practices. The overall knowledge gain of 25% was statistically significant (p < .01). Workers recalled at least one key concept, expressed confidence of adopting at least one safety behavior, and mentioned their intention to communicate safety concerns to farmers. To our knowledge, this is the first Taxonomy of Significant Learning application to occupational safety and health education. Our curriculum can support dairy farmers’ compliance with Occupational Safety and Health Administration’s annual training requirements by providing our basic safety and health training to workers at early job stages.

Sorting Through the Spheres of Influence: Using Modified Pile Sorting to Describe Who Influences Dairy Farmers’ Decision-Making About Safety

ABSTRACT Objectives: The primary goal of this study was to describe the mutually perceived influence of bankers and insurers on their agricultural clients’ decision-making regarding health and safety. Methods: Semistructured interviews were conducted with 10 dairy farmers, 11 agricultural bankers, and 10 agricultural insurers from central Wisconsin. Three of the interview questions involved pile sorting. Pile sorting included 5-point Likert-like scales to help participants sort through 32 index cards. Each card represented an individual or group that was thought to possibly affect farmers’ decision-making, both generally and about health and safety. Results (photographs of piles of cards quantified into spread sheets, fieldnotes, and interview transcripts) were analyzed with SAS and NVivo. Results: All three groups expressed moderate-to-strong positive opinions about involving agricultural bankers (x2(2) = 2.8155, p = 0.2695), although bankers qualitatively expressed apprehension due to regulations on the industry. Insurance agents received more positive support, particularly from bankers but also from dairy farmers themselves, and expressed more confidence in being involved in designing and implementing a farm safety program. Conclusion: Agricultural bankers and insurers can influence individual farmer’s decision-making about health and safety. Both are believed to be good purveyors of safety programs and knowledge, especially when leveraging financial incentives. Insurance agents are thought to be more critical in the design of safety programs. Insurers and bankers being financially tied to safety programs may prove both positive and negative, as farmers may be skeptical about the intention of the incentives, making messaging critical.

The Use of Audience Response System Technology With Limited-English-Proficiency, Low-Literacy, and Vulnerable Populations

ABSTRACT Audience response systems (ARS) have long been used to improve the interactivity of educational activities. Most studies of ARS have addressed education of literate trainees. How well these devices work with low-literacy subjects is not well studied. Information gathering on the training audience is an important use of ARS and helpful in improving the targeting of training information. However, obtaining demographic information from vulnerable populations with reasons to be concerned about divulging information about themselves has not been tested. In addition, a culturally competent method to effectively collect demographic and evaluation data of this growing population is essential. This project investigated the use of ARS to gather information from Hispanic immigrant workers, many of whom are socially vulnerable and have limited English proficiency (LEP) and low-literacy. Workers attended focus groups and were asked to use ARS devices or clickers to respond to questions. Questions were both categorical (multiple choice) and open-ended numerical (text entry), and varied from simple queries to more sensitive points regarding immigration. Most workers answered the one-key response categorical questions with little difficulty. In contrast, some participants struggled when responding to numerical questions, especially when the response required pressing multiple clicker keys. An overwhelming majority of participants reported that the clickers were comfortable and easy to use despite the challenges presented by the more complex responses. The error rate increased as question complexity increased and the trend across three ordered categories of response complexity reached statistical significance. Results suggest that ARS is a viable method for gathering dichotomous or higher-order categorical information from LEP and low-literacy populations in a group setting while assuring anonymity. However, it is recommended that clickers be developed and tested with fewer, bigger, and more widely separated buttons, and less printing on the buttons for these populations. Further research is needed to determine the effectiveness of using clickers with simplified configurations in the workplace as a tool to collect data for surveys and assessments and to better engage LEP and low-literacy workers in training sessions.

A Model Health and Safety Intervention for Hispanic Immigrants Working in the Dairy Industry

A Model Health and Safety Intervention for Hispanic Immigrants Working in the Dairy Industry Amy K. Liebman MPA, MA, Patricia Juarez-Carrillo MPH, PhD, Iris Anne C. Reyes MPH & Matthew C. Keifer MD, MPH a Amy K. Liebman and Patricia Juarez-Carrillo are affiliated with the Migrant Clinicians Network, Salisbury, Maryland, USA. b Iris Anne C. Reyes and Matthew C. Keifer are affiliated with the National Farm Medicine Center, Marshfield Clinic Research Foundation, Marshfield, Wisconsin, USA. Published online: 09 Jun 2014.

Blood α-synuclein in agricultural pesticide handlers in central Washington State

Epidemiologic studies suggest that occupational exposure to pesticides might increase Parkinson disease risk. Some pesticides, such as the organophosphorus insecticide chlorpyrifos, appear to increase the expression of α-synuclein, a protein critically involved in Parkinson disease. Therefore, we assessed total blood cell α-synuclein in 90 specimens from 63 agricultural pesticide handlers, mainly Hispanic men from central Washington State, who participated in the states cholinesterase monitoring program in 2007-2010. Additionally, in age-adjusted linear regression models for repeated measures, we assessed whether α-synuclein levels were associated with butyrylcholinesterase-chlorpyrifos adducts or cholinesterase inhibition measured in peripheral blood, or with self-reported pesticide exposure or paraoxonase (PON1) genotype. There was no evidence by any of those indicators that exposure to chlorpyrifos was associated with greater blood α-synuclein. We observed somewhat greater α-synuclein with the PON1-108T (lower paraoxonase enzyme) allele, and with ≥ 10 h of exposure to cholinesterase inhibiting insecticides in the preceding 30 days, but neither of these associations followed a clear dose-response pattern. These results suggest that selected genetic and environmental factors may affect α-synuclein blood levels. However, longitudinal studies with larger numbers of pesticide handlers will be required to confirm and elucidate the possible associations observed in this exploratory cross-sectional study.