Rationale. The agricultural work environment is potentially hazardous to farm workers’ respiratory health. Several respiratory diseases and symptoms have been linked to airborne pollutants found in the agricultural work environment. Additionally, those who have immigrated to the United States (U.S.) from Mexico or Central America tend to experience worsening health outcomes with increased time in the U.S., a phenomenon known as the Hispanic Epidemiologic Paradox. Identifying specific factors contributing to the elevated prevalence of respiratory diseases and symptoms in immigrants from Mexico or Central America who engage in agricultural work is necessary to determine the appropriate public health response needed to decrease respiratory disease prevalence in this population.

Methods. A random sample of heads of households of Mexican and Central American origin who reside in Mendota, CA and had performed farm work in the past year, along with their partners, were given an interviewer-administered survey that assessed agricultural work history and dust exposure (years worked, past year dust exposure, and use of personal protective equipment), acculturation, age at immigration, years in the U.S., and respiratory health history. Contingency table analysis and multivariate logistic regression models were used to examine how the risk for respiratory diseases and symptoms varies with agricultural work exposures and acculturation and immigration-related factors.

Results. We interviewed 875 residents of Mendota, 737 of whom had engaged in farm work in the past year. In logistic regression models adjusted for age, gender, and smoking status, number of years worked in agriculture was associated with chronic cough (AOR=1.08, 95% CI, 1.01-1.15) and asthma (AOR=1.04, 95% CI, 1.00-1.08). In similar logistic regression models, self-reported dust exposures were not statistically significantly associated with respiratory diseases or symptoms in this sample. Multivariate logistic regression models specified gender-specific odds ratio estimates for acculturation on each of the respiratory outcomes, adjusting for age and smoking status. In women (n=319), acculturation was a statistically significant risk factor for three respiratory outcomes—asthma (AOR= 5.92, 95% CI, 1.71-20.46), chronic bronchitis (AOR=6.69, 95% CI, 1.30-34.44), and persistent wheeze (AOR=4.47, 95% CI, 1.01-19.69)—but not chronic cough (AOR=3.50, 95% CI, .43-28.21). The corresponding coefficients for men (n=418) were not significant for any of the outcomes: asthma (AOR=2.07, 95% CI, .55-7.70), chronic cough (AOR=1.23, 95% CI, .20-7.56), chronic bronchitis (AOR=1.92, 95% CI, .39-9.51), and persistent wheeze (AOR=1.73, 95% CI, .42-7.05). Years in the U.S. and a younger age at immigration also increased the odds of asthma in women.

Conclusion. In our cross-sectional study of Hispanic farm workers residing in Mendota, CA, number of years worked in agriculture was associated with chronic cough and asthma. No relationship between subjective dust exposure and adverse respiratory outcomes was observed, but future quantification of dust exposure through objective measurements is needed to understand the impact of cumulative and recent dust exposure on respiratory health. Acculturation and immigration-related factors had a significant and strong association with women's respiratory health: a medium/high acculturation level and a greater number of years spent in the U.S., as well as younger age at immigration, negatively affected women's respiratory health. This suggests that adaptation to a new lifestyle and environment in the U.S. may adversely affect respiratory health in women. This phenomenon was not observed in men, and thus gender-specific interventions may be valuable. Acculturation and proxies of it have previously been found to exert a stronger influence on negative health behaviors in women than in men. Identifying the behaviors in highly acculturated women and the U.S. environmental factors that contribute to declining respiratory health is the next step to implementing effective interventions.