Epidemic Asthma in Barcelona: An Evaluation of New Strategies for the Control of Soybean Dust Emission

Abstract

Background: Asthma attacks and mortality due to inhalation of soybean antigens in Barcelona have been well documented. Strict protective measures in the unloading process were established in 1998 to avoid the release of soybean dust into the atmosphere. The present study was undertaken to assess the effectiveness of these latest environmental measures, and, if effective, to recommend their implementation in the many harbours where soybean is unloaded. Methods: Levels of soybean aeroallergen were analysed daily during a period of 5 years and 2 months in a total of 1,854 samples, 125 from the pre-intervention period and 1,729 from the postintervention period. Additionally, the number of asthma admissions to the emergency rooms of the city’s three largest hospitals was recorded. Asthma patients attended at home by the public home emergency service and judicial autopsies registering asthma deaths were also investigated. Results: The mean concentration of soybean aeroallergen was 159 U/m³ in the pre-intervention period and 39 U/m³ in the postintervention period (p < 0.0001). Significant differences in postintervention aeroallergen concentrations were found between days of soybean unloading (42 U/m³) and days of no unloading (33 U/m³), with p < 0.0001. No significant relationship was found between concentrations of environmental soybean aeroallergens and the number of emergency room admissions for asthma. Conclusions: Implementation of stricter protective measures in silos for the soybean unloading process has reduced the concentration of soybean dust in the atmosphere and evidences the effectiveness of the measures adopted.

Allergic reactions to foods by inhalation

“…Asthma attacks and mortality due to inhalation of soybean antigens in Barcelona have also been documented [ 28 ]. Strict protective measures in the unloading process were established in 1998 to avoid the release of soybean dust into the atmosphere.…”

A Rapid Test for Soy Aeroallergens Exposure Assessment

“…One of the measures adopted in Barcelona is daily soy monitoring in a district close to the harbor using a large-volume automated air sampler, as a means of determining the exposure in the population [11]. From autumn 1997 to May 2012 these measurements were performed by an enzyme immunoassay (EIA) inhibition assay using a serum pool with specific immunoglobulin E (IgE) antibodies from subjects allergic to soybean as a detector antibody [10], [11].…”

“…From autumn 1997 to May 2012 these measurements were performed by an enzyme immunoassay (EIA) inhibition assay using a serum pool with specific immunoglobulin E (IgE) antibodies from subjects allergic to soybean as a detector antibody [10], [11]. Levels of soy aeroallergens should not exceed two threshold values: the Environmental High Threshold Limit Value (EH-TLV, set at 480 U/m 3 ), and the Environmental Low Threshold Limit Value (EL-TLV, set at 160 U/m 3 ).…”

Does Sensitization to Foods in Adults Occur Always in the Gut?

“…In adults, soybean sensitization seems to occur via the respiratory tract not only for Gly m1, the inedible allergen of soybean hull involved in epidemic asthma breakdowns, but also for the food allergens of soy flour in exposed workers both in bakeries and food processing plants [62,63]. …”