Sulfur Used as pesticide linked to respiratory problems in children

Elemental sulfur, “the oldest of all pesticides,” is the most heavily used agricultural pesticide in California and Europe. Sulfur is considered relatively safe and is used in both conventional and organic farming systems. Adverse respiratory effects have been reported in applicators and animals, but the effect on residential populations, and especially on children living in proximity to fields treated with elemental sulfur, is not known.

Rachel Raanan et al.evaluated associations between residential proximity to elemental sulfur applications and respiratory symptoms and spirometry of children living in an agricultural community and presented their longitudinal birth cohort study online August 14 in Environmental Health Perspectives.

The participants were enrolled in the CHAMACOS longitudinal birth cohort. The researchers collected respiratory symptomatology for 347 children at 7 y of age and measured spirometry on a subset of 279. Of these, estimations of proximity to sulfur application and relevant covariate data were available for 237 and 205 children for whom we had symptomatology information and FEV₁ measurements, respectively. Data from the California Pesticide Use Reporting System were used to estimate the amount of elemental sulfur applied within 0.5, 1, and 3 km of a child’s residence during the week, month, and 12 mo prior to pulmonary evaluation. Regression models controlled for maternal smoking during pregnancy; season of birth; PM_2.5 (particulate matter ≤2.5 mm in aerodynamic diameter); breast feeding duration; child’s sex, age, and height; technician; and other covariates.

It was found that there were adverse associations with respiratory outcomes for sulfur applications within 0.5- and 1-km radii. Specifically, asthma medication usage and respiratory symptoms increased [OR=3.51; 95% confidence interval (CI): 1.50, 8.23, p=0.004; OR=2.09; 95% CI: 1.27, 3.46, p=0.004, respectively] and FEV₁ decreased (β=−0.143; 95% CI: −0.248, −0.039, p=0.008) per 10-fold increase in the estimated amount of sulfur used within 1 km of child residence during the year prior to pulmonary evaluation.

It was concluded that elemental sulfur use, allowed in both organic and conventional farming, in close proximity to residential areas, may adversely affect children’s respiratory health.The findings also suggest that exposure to low levels of elemental sulfur produces a restrictive effect on children's lungs that is similar to the effect caused by early-life exposure to organophosphate pesticides,The potential respiratory toxicity of elemental sulfur deserves more regulatory attention keeping in view its widespread use worldwide.