This study proposes to explore the associations between occupational exposure to lobster and saltwater bony fish (pilchard, Cape anchovy, mackerel, light fish, redeye, Cape horse mackerel, lantern fish) and health outcomes expected to be mediated through an immunologic IgE mechanism. The research proposes to investigate occupational asthma and other allergic conditions associated with rock lobster and saltwater bony fish processing in South Africa. Ingestion related seafood allergy is a common problem in the general population. Allergic reactions most often related to inhalation of antigens have been increasingly recognized as a serious problem among seafood workers. The predictors of occupational sensitization and health outcomes associated with lobster and bony fish processing are not well understood.Exposure-response relationships for occupational seafood allergy have been best characterized for exposure to a few crustaceans notably crab species. No published studies have examined this problem among workers exposed to crustaceans and bony fish common in the South Atlantic. A cross-sectional study is proposed to characterize the occupational environmental exposure of workers in a factory on the West Coast of South Africa, involved in the processing of rock lobster and saltwater bony fish (pilchard, Cape anchovy, mackerel, light fish, redeye, Cape horse mackerel, lantern fish) through measurement of total protein and specific allergen collected by air sampling.
A second aim i s to determine the prevalence of allergic sensitization and health outcomes (rhino-conjunctivitis, urticaria/dermatitis and asthma) due to processing of rock lobster and saltwater bony fish through subject interviews, physical examination (skin), spirometry and methacholine challenge tests, skin prick tests (for common aeroallergens and specific seafood allergens) and skin patch testing. The third major aim is to characterize the relationship between exposure (measured as ambient concentrations of total protein and specific RAST inhibition), allergic responses to lobster and bony-fish allergens, and lung function changes. Statistical modeling will be used to identify the risk factors associated with the development of seafood allergy among seafood processing workers. Another aim is to isolate and characterize the seafood antigens present in aerosols generated during the processing of West Coast rock lobster and saltwater bony fish.
The final aim i s to investigate the extent to which any exposure response relationships are attenuated by the transfer of symptomatic workers from high to low exposure jobs. The development and application of state of the art techniques to address the specific aims is proposed. Potential public health benefits of this study would be the development of appropriate industrial hygiene monitoring techniques and medical surveillance protocols for monitoring the health of workers exposed to seafood allergens. By characterizing the occupational exposures among these high risk working populations. This study will also contribute towards a better understanding of the antigenic mechanisms causing seafood allergy among symptomatic individuals in the general population of the Western Cape province of South Africa and internationally.
