Respiratory symptomsinarable farmworkers: role ofstorage mites

Storage mites (acarid mites) arerelated tothehousedustmitebutare usually foundin agricultural environments. Theyhavebeenshownto cause allergic symptoms inScottish farmworkers exposed tostored hay, butwhether farmworkers whogrow andstoregrain arealso at risk isunknown. Onehundred andone farmworkers on 22Essexfarms withgrain storagefacilities (88%oftheavailable workforce) participated inasurveyofrespiratory symptoms,withskin tests and determination ofserumlevels ofIgEspecific formitespecies, including storagemites. Ofthe101 workers, 21reported attacks ofcough, wheeze, orbreathlessness after exposure tostored grain and 15reported nasal symptomsafter grain exposure.Storage mitespecific IgEwas foundin59%of farmworkers withworkrelated respiratory symptoms,in60%withworkrelated nasal symptoms, andinonly9% ofsymptomless farmworkers. Workrelated respiratory andnasal symptomswere also significantly associated with atopy,andwithpositive skin test responsesandserum IgEspecific forDermatophagoides pteronyssinus. Storage mites werefoundingrain samples from16farmsin whichgrain was sampled, whereas D pteronyssinus was notfoundinany. Theclose association between serum storage mitespecific IgEandoccupational respiratory symptomssuggeststhat storage mites may beresponsible forrespiratory symptomsinthese Essexfarmworkers exposed to grain.