O1D.3 Fumigant and chemical residue 8-hour exposures in workers handling cargo from shipping containers and export logs in new zealand

BackgroundPrevious studies found elevated concentrations of fumigants and other chemicals in the air of unopened shipping containers, which led to the assumption that workers were likely to be highly exposed. This study assessed personal 8 hour exposures in workers handling cargo from shipping containers or export logs, which were fumigated prior to loading.Methods193 personal 8 hour air samples were collected and analysed for 1,2-dibromoethane, chloropicrin, ethylene oxide, hydrogen cyanide, hydrogen phosphide and methyl bromide, 1,2-dichloroethane, C2-alkylbenzenes, acetaldehyde, ammonia, benzene, formaldehyde, methanol, styrene and toluene. Additive Mixture Values were calculated using the Work Exposure (WES) standard set by Worksafe NZ and the Threshold Limit Values (TLV) set by the ACGIH. Linear regression was conducted to assess associations between time spent inside shipping containers and exposure (n=98).ResultsChemical exposures as indicated by median and geometric mean values were low (e.g. 2.5 and 4.4 ppb respectively for methyl bromide) and none exceeded the NZ WES, although formaldehyde exceeded the TLV in 48 (26.2%) samples. The AMV-TLV threshold of 1 was exceeded in 54 (29.5%) samples. Major differences between the occupational groups (container, log and retail workers and fumigators) were not found. Time spent inside the container was significantly and positively associated with ethylene oxide, C2-alkylbenzenes and acetaldehyde, but this was based on a small number of detectable observations (non-detects 52.0%–95.9%) and for one chemical (methyl bromide, n=94) we found inverse associations.ConclusionThis study has shown that personal exposures measured over an 8 hour working day were low, with the exception of formaldehyde, and do not confirm earlier suggestions (based on measurements inside closed containers) that they regularly exceed exposure limits. Association with time spent unloading containers was weak suggesting that exposures may result from short peak exposures rather than continuous low level exposure.