Pyrethroid Levels Amplify Asthma Severity in Children via Elevating Eosinophils, IgE, and Compromising Lung Function

Pesticide exposure in children, particularly through inhalation, is known to exacerbate asthma and contribute to its development, often originating from indoor sources and residues. This study investigates the levels of various pesticides (organophosphate, organochlorine, and pyrethroid groups) and their association with allergic markers such as eosinophils and IgE levels, as well as airway obstruction, specifically forced expiratory volume (FEV1), in asthmatic children compared to controls. A total of 200 participants, including 100 asthmatic children and 100 age- and gender-matched controls, were enrolled. Serum pesticide levels were quantified using gas chromatography-tandem mass spectrometry, while IgE levels were assessed by immunoturbidimetry assay. Eosinophil counts were measured using a 5-part hematology analyzer (Abbott Alinity h-series), and FEV1 was evaluated with a Spirolab device. Among 140 screened pesticides, four pyrethroids-metofluthrin, allethrin, imiprothrin, and transfluthrin were identified and their levels found significantly higher in asthmatic children compared to controls (p < 0.05). Increased eosinophil counts, elevated serum IgE levels, and reduced FEV1 were observed in asthmatic children (p < 0.05). Positive correlations were found between eosinophil and IgE levels with metofluthrin (r = 0.40, p < 0.0001; r = 0.39, p < 0.0001), allethrin (r = 0.45, p < 0.0001; r = 0.47, p < 0.0001), and imiprothrin (r = 0.498, p < 0.0001; r = 0.401, p < 0.0001), transfluthrin (r = 0.31, p = 0.038; r = 0.36, p = 0.006). The results indicate that exposure to common household pesticides such as transfluthrin, allethrin, metofluthrin, and imiprothrin triggers allergic reactions and exacerbates asthma severity in children.

The online version contains supplementary material available at https://doi.org/10.1007/s12291-024-01285-x.