[Soybean hull unloading in Tarragona (Spain) and asthma outbreak risk].
OBJECTIVE
From 2007 to 2008, 215,000 tons of soybean hull were unloaded in the Port of Tarragona. Soybean hull was identified as the etiologic agent causing bronchial asthma outbreaks. The aim of the present study was to identify the characteristics of soybean unloading, soybean allergen dispersion, and the population risk.


METHODS
Data on soybean hull unloading, carriage and storage, meteorological conditions and the number of emergency room admissions for asthma were recorded. Allergen concentrations were obtained by sampling PM(10) filters retaining particles of less than 10 microns for 24 hours in the atmospheric contamination surveillance stations. Sensitized patients underwent clinical examination consisting of skin prick test, total and specific IgE and immunoblotting to soybean extracts.


RESULTS
Allergen emissions were moderate at one kilometer from the unloading source (above 300 U/m(3) on 3 days, maximum 441 U/m(3)). The protein pattern of hull soybean extracts was similar to that found in asthma epidemics in Barcelona. Ninety-two percent of the patients were sensitized to soybean hull extracts. No asthma epidemic was detected during unloading days. In addition to the low molecular weight soybean proteins identified in previous studies (6 and 14-17 kDa), high molecular weight proteins were found (14-49 kDa).


CONCLUSIONS
There is allergen dispersion at a short distance from the unloading source, posing a risk to sensitized patients. Technical measures are required during soybean hull operations to reduce particle emissions.
Rovira
Enric
E
Observatori de Salut i Medi Ambient del Camp de Tarragona, Servei Regional al Camp de Tarragona de l'Agència de Protecció de la Salut, Tarragona, Spain. enric.rovira@gencat.cat
Cuadras
Anna
A
Gaig
Pere
P
Gázquez
Vanessa
V
Dalmau
Gaspar
G
Gómez-Ollés
Susana
S
Cruz
Ma Jesús
MJ
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D052179:Antigens, Plant / Q000009:adverse effects*; D001249:Asthma / Q000453:epidemiology* / Q000209:etiology*; D004196:Disease Outbreaks; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000453:epidemiology* / Q000209:etiology*; D012307:Risk Factors; D013025:Glycine max; D013030:Spain
D052179:Antigens, Plant