Occupational allergies in the seafood industry: a comparative study of Australian and South African workplaces

Although seafood allergy due to ingestion is commonly observed in clinical practice, the incidence of seafood allergies in general and more specifically in the occupational setting in Australia is largely unknown. The work practices, occupational health services and allergic health problems in 140 seafood processing workplaces in Australia were examined and compared to previous studies in South Africa. A cross-sectional employer-based survey design was used to conduct the study in both countries. In the South African study a response rate of 60% (n = 41) was obtained, compared to a response rate of 18% (n = 140) in Australia. The most common seafood processed by workplaces in South Africa was finfish (76%) and rock lobster (34%). Similarly in Australia, finfish (34%) was the most frequently handled seafood. However, processing of prawns (24%) and oysters (21%) was more common in Australia. Common work processes in South Africa involved freezing (71%), cutting/filleting (63%) and degutting (58%) procedures. Similar processes were followed in Australian industries with the exception of shucking of oysters, particularly common in the aquaculture industries. About half of the workplaces in both countries provided an occupational health service and medical surveillance of workers. However, none of the workplaces in South Africa and only 9% of the workplaces in Australia had industrial hygiene programs for seafood aerosols in place. In both countries positive trends were observed between the size of the workforce and the provision of occupational health services (p<0.005). Similarly, skin rash accounted for highest of all reported health problems (78-81%) followed by asthmatic symptoms (7-10%) and other non-specific allergic symptoms (9-15%) in both countries. Most workplaces reported the annual prevalence of work-related symptoms to be less than 5%. In Australia 7% of respondents in workplaces reported workers having left their workplace due to work-related allergic problems. Despite a low response rate of contacted companies in Australia, there were great similarities between the two countries suggesting that there is a significantly elevated prevalence of work related allergic symptoms in both countries. Unexpectedly, mollusc processing was more common in Australia although the occupational health related effects among exposed workers has previously not been investigated in detail and merits further study. It is recommended that further epidemiological studies focus on seafood exposure in Australia and identify specific risk factors for sensitisation

The microbiological status of prawns from retail and wholesale outlets in the Brisbane region

Cooked prawns from retail and wholesale outlets in the Brisbane region included a large proportion with high bacterial counts (10(6)-10(8)/g) indicating a short remaining shelflife. Microbially inferior product entering the wholesale and retail trade indicated poor handling and storage practices from point of capture all along the distribution chain to the retail outlets. Current handling practices need to be upgraded and HACCP principles adopted

Spoilage pattern of five species of Australian prawns: Deterioration is influenced by environment of capture and mode of storage

Five species of commercial prawns Penaeus plebejus, P. merguiensis, P. semisulcatus/P. esculentus and M. bennettae, were obtained from South-East and North Queensland, chilled soon after capture and then stored either whole or deheaded on ice and ice slurry, until spoilage. Total bacterial counts, total volatile nitrogen, K-values and total demerit scores were assessed at regular intervals. Their shelf lives ranged from 10-17 days on ice and >20 days on ice slurry. Initial bacterial flora on prawns from shallower waters (4-15m) were dominated by Gram-positives and had lag periods around 7 days, whereas prawns from deeper waters (100m) were dominant in Pseudomonas spp. with no lag periods in bacterial growth. The dominant spoiler in ice was mainly Pseudomonas fragi whereas the main spoiler in ice slurry was Shewanella putrefaciens. Bacterial interactions seem to play a major role in the patterns of spoilage in relation to capture environment and pattern of storag

The microbiological status of prawns from retail and wholesale outlets in the Brisbane region

Cooked prawns from retail and wholesale outlets in the Brisbane region included a large proportion with high bacterial counts (10(6)-10(8)/g) indicating a short remaining shelflife. Microbially inferior product entering the wholesale and retail trade indicated poor handling and storage practices from point of capture all along the distribution chain to the retail outlets. Current handling practices need to be upgraded and HACCP principles adopted

Spoilage pattern of five species of Australian prawns: Deterioration is influenced by environment of capture and mode of storage

Five species of commercial prawns Penaeus plebejus, P. merguiensis, P. semisulcatus/P. esculentus and M. bennettae, were obtained from South-East and North Queensland, chilled soon after capture and then stored either whole or deheaded on ice and ice slurry, until spoilage. Total bacterial counts, total volatile nitrogen, K-values and total demerit scores were assessed at regular intervals. Their shelf lives ranged from 10-17 days on ice and >20 days on ice slurry. Initial bacterial flora on prawns from shallower waters (4-15m) were dominated by Gram-positives and had lag periods around 7 days, whereas prawns from deeper waters (100m) were dominant in Pseudomonas spp. with no lag periods in bacterial growth. The dominant spoiler in ice was mainly Pseudomonas fragi whereas the main spoiler in ice slurry was Shewanella putrefaciens. Bacterial interactions seem to play a major role in the patterns of spoilage in relation to capture environment and pattern of storag

Dynamic Microstructural Evolution of Graphite under Displacing Irradiation

Graphitic materials and graphite composites experience dimensional change when exposed to radiation-induced atomic displacements. This has major implications for current and future technological ranging from nuclear fission reactors to the processing of graphene-silicon hybrid devices. Dimensional change in nuclear graphites is a complex problem involving the filler, binder, porosity, cracks and atomic-level effects all interacting within the polygranular structure. An improved understanding of the atomistic mechanisms which drive dimensional change within individual graphitic crystals is required to feed into the multiscale modelling of this system. In this study, micromechanically exfoliated samples of highly oriented pyrolytic graphite have been ion irradiated and studied in situ using transmission electron microscopy (TEM) in order to gain insights into the response of single graphitic crystals to displacing radiation. Under continuous ion bombardment, a complex dynamic sequence of deformation evolves featuring several distinct stages from the inducement of strain, the creation of dislocations leading to dislocation arrays, the formation of kink band networks and localised doming of the sample. Observing these ion irradiation-induced processes using in situ TEM reveals previously unknown details of the sequence of microstructural developments and physics driving these phenomena. A mechanistic model consistent with the microstructural changes observed is presented