Mateus dos Santos

Occupational Exposure to Aflatoxin B1 in a Portuguese Poultry Slaughterhouse

Aflatoxin B1 (AFB1) is a secondary metabolite produced by the fungi Aspergillus flavus and is the most potent hepatocarcinogen known in mammals and has been classified by the International Agency of Research on Cancer as Group 1 carcinogen. Although dietary exposure to AFB1 has been extensively documented, there are still few studies dedicated to the problem of occupational exposure. Considering recent findings regarding AFB1 occupational exposure in poultry production, it was considered relevant to clarify if there is also exposure in poultry slaughterhouses. Occupational exposure assessment to AFB1 was done with a biomarker of internal dose that measures AFB1 in the serum by enzyme-linked immunosorbent assay. Thirty workers from a slaughterhouse were enrolled in this study. A control group (n = 30) was also considered in order to know AFB1 background levels for Portuguese population. Fourteen workers (47.0%) showed detectable levels of AFB1 with values from 1.06 to 4.03ng ml(-1), with a mean value of 1.73ng ml(-1). No AFB1 was detected in serum of individuals used as controls. Despite uncertainties regarding the exposure route that is contributing more to exposure (inhalation or dermal) is possible to state that exposure to AFB1 is occurring in the slaughterhouse studied. It seems that reducing AFB1 contamination in poultry production can have a positive result in this occupational setting.

Slaughterhouses Fungal Burden Assessment: A Contribution for the Pursuit of a Better Assessment Strategy

In slaughterhouses, the biological risk is present not only from the direct or indirect contact with animal matter, but also from the exposure to bioaerosols. Fungal contamination was already reported from the floors and walls of slaughterhouses. This study intends to assess fungal contamination by cultural and molecular methods in poultry, swine/bovine and large animal slaughterhouses. Air samples were collected through an impaction method, while surface samples were collected by the swabbing method and subjected to further macro- and micro-scopic observations. In addition, we collected air samples using the impinger method in order to perform real-time quantitative PCR (qPCR) amplification of genes from specific fungal species, namely A. flavus, A. fumigatus and A. ochraceus complexes. Poultry and swine/bovine slaughterhouses presented each two sampling sites that surpass the guideline of 150 CFU/m3. Scopulariopsis candida was the most frequently isolated (59.5%) in poultry slaughterhouse air; Cladosporium sp. (45.7%) in the swine/bovine slaughterhouse; and Penicillium sp. (80.8%) in the large animal slaughterhouse. Molecular tools successfully amplified DNA from the A. fumigatus complex in six sampling sites where the presence of this fungal species was not identified by conventional methods. This study besides suggesting the indicators that are representative of harmful fungal contamination, also indicates a strategy as a protocol to ensure a proper characterization of fungal occupational exposure.

Assessment of exposure to the Penicillium glabrum complex in cork industry using complementing methods

Abstract Cork oak is the second most dominant forest species in Portugal and makes this country the world leader in cork export. Occupational exposure to Chrysonilia sitophila and the Penicillium glabrum complex in cork industry is common, and the latter fungus is associated with suberosis. However, as conventional methods seem to underestimate its presence in occupational environments, the aim of our study was to see whether information obtained by polymerase chain reaction (PCR), a molecular-based method, can complement conventional findings and give a better insight into occupational exposure of cork industry workers. We assessed fungal contamination with the P. glabrum complex in three cork manufacturing plants in the outskirts of Lisbon using both conventional and molecular methods. Conventional culturing failed to detect the fungus at six sampling sites in which PCR did detect it. This confirms our assumption that the use of complementing methods can provide information for a more accurate assessment of occupational exposure to the P. glabrum complex in cork industry. Hrast plutnjak druga je vrsta po učestalosti u portugalskim šumama, zbog čega je ta zemlja najveći izvoznik pluta na svijetu. Profesionalna je izloženost plijesnima Chrysonilia sitophila i Penicillium glabrum česta u proizvodnji pluta, a potonja vrsta povezana je s plućnom bolesti suberozom. Međutim, prilikom procjene izloženosti konvencionalnim se metodama često podcjenjuje prisutnost te vrste u radnom okolišu. Stoga je cilj ovog istraživanja bio provjeriti pretpostavku da polimerazna lančana reakcija (PCR) kao molekulska metoda dopunjuje nalaze konvencionalnih metoda i time daje bolji uvid u profesionalnu izloženost radnika u proizvodnji pluta. U tu smo svrhu istražili onečišćenje kompleksom P. glabrum u trima tvornicama pluta u okolici Lisabona oslanjajući se na konvencionalne i molekulske metode. PCR je otkrio prisutnost plijesni u šest uzoraka, u kojih konvencionalne metode nisu otkrile njihovu prisutnost. To potvrđuje našu pretpostavku da se primjenom komplementarnih metoda može steći bolji uvid i napraviti točnija procjena profesionalne izloženosti kompleksu P. glabrum u proizvodnji pluta.

Microbiota and Particulate Matter Assessment in Portuguese Optical Shops Providing Contact Lens Services

The aim of this work was to assess the microbiota (fungi and bacteria) and particulate matter in optical shops, contributing to a specific protocol to ensure a proper assessment. Air samples were collected through an impaction method. Surface and equipment swab samples were also collected side-by-side. Measurements of particulate matter were performed using portable direct-reading equipment. A walkthrough survey and checklist was also applied in each shop. Regarding air sampling, eight of the 13 shops analysed were above the legal requirement and 10 from the 26 surfaces samples were overloaded. In three out of the 13 shops fungal contamination in the analysed equipment was not detected. The bacteria air load was above the threshold in one of the 13 analysed shops. However, bacterial counts were detected in all sampled equipment. Fungi and bacteria air load suggested to be influencing all of the other surface and equipment samples. These results reinforce the need to improve air quality, not only to comply with the legal requirements, but also to ensure proper hygienic conditions. Public health intervention is needed to assure the quality and safety of the rooms and equipment in optical shops that perform health interventions in patients.

Filters from taxis air conditioning system: A tool to characterize driver's occupational exposure to bioburden?

&NA; Bioburden proliferation in filters from air conditioning systems of taxis represents a possible source of occupational exposure. The aim of this study was to determine the occurrence of fungi and bacteria in filters from the air conditioning system of taxis used for patient transportation and to assess the exposure of drivers to bioburden. Filters from the air conditioning systems of 19 taxis and 28 personal vehicles (used as controls) operating in three Portuguese cities including the capital Lisbon, were collected during the winter season. The occurrence and significance of bioburden detected in the different vehicles are reported and discussed in terms of colony‐forming units (CFU) per 1 m2 of filter area and by the identification of the most frequently detected fungal isolates based on morphology. Azole‐resistant mycobiota, fungal biomass, and molecular detection of Aspergillus species/strains were also determined. Bacterial growth was more prevalent in taxis (63.2%) than in personal vehicles (26.3%), whereas fungal growth was more prevalent in personal vehicles (53.6%) than in taxis (21.1–31.6%). Seven different azole‐resistant species were identified in this study in 42.1% taxi filters. Levels of fungal biomass were above the detection limit in 63% taxi filters and in 75% personal vehicle filters. No toxigenic species were detected by molecular analysis in the assessed filters. The results obtained show that bioburden proliferation occurs widely in filters from the air conditioning systems of taxis, including the proliferation of azole‐resistant fungal species, suggesting that filters should be replaced more frequently. The use of culture based‐methods and molecular tools combined enabled an improved risk characterization in this setting. HighlightsFilters from air conditioning system are a suitable method to characterize bioburden in vehicles.Fungi and bacteria occur widely in taxis and personal vehicles.The genera Aspergillus, Cladosporium and Penicillium were often detected.Filters should be more frequently replaced to avoid bioburden proliferation and reaerosolization.Culture based and molecular methods used in parallel enabled an improved risk characterization.

Task-based occupational exposure assessment and particle number concentration: Two important data resources to perform risk assessment for occupational exposure to particles

Negative health effects because of poor work environment is more common among young workers compared to older. One explanation might be that younger ones have a low awareness of risk, a lack of safety training, and inadequate introductions to the work. A study has been made focusing on the pupils in vocational schools knowledge and experiences about potential work environment risks in their future work. Questionnaires were distributed to 239 pupils in ten Swedish upper secondary schools’ graduating classes in four vocational programs focusing on basic knowledge about health risks at work as well as the work environment legislation. The programs were the Industrial Technology Program, the Restaurant Management and Food Program, the Transport Program, and the Handicraft Program (in which students specialize in wood). The results from the questionnaires were followed up with focus group discussions. The results showed that the pupils in general had limited knowledge that employers must, by law, conduct risk analyses and prevent risks. It was common that they mentioned themselves as the main responsible to work safe and was not clear about the employers’ duty to arrange for safe work. Pupils in all programs mentioned acute risk as the biggest risk at work. It was concluded that a systematic approach to pupils’ training in work environment is lacking. The results indicates a clear gap between what knowledge the pupils are offered and what’s intended by laws as well as state-of-the-art in occupational health risk research.