Time filter

Source Type

Van Der Walt A.,University of Cape Town | Singh T.,National Institute for Occupational Health NIOH | Singh T.,University of Witwatersrand | Baatjies R.,University of Cape Town | And 4 more authors.
Occupational and Environmental Medicine | Year: 2013

Objective The aim of the study was to determine the prevalence and risk factors for allergic respiratory disease in spice mill workers. Methods A cross-sectional study of 150 workers used European Community Respiratory Health Survey questionnaires, Phadiatop, serum specific IgE (garlic, chili pepper), spirometry and fractional exhaled nitric oxide (FeNO). Personal air samples (n=62) collected from eight-hour shifts were analysed for inhalable particulate mass. Novel immunological assays quantified airborne garlic and chili pepper allergen concentrations. Results Mean dust particulate mass (geometric mean (GM)=2.06 mg/m3), chili pepper (GM=0.44 mg/m3) and garlic allergen (GM=0.24 mg/m3) were highest in blending and were highly correlated. Workers' mean age was 33 years, 71% were men, 46% current smokers and 45% atopic. Spice-dust-related asthma-like symptoms (17%) were common, as was garlic sensitisation (19%), with 13% being monosensitised and 6% cosensitised to chili pepper. Airflow reversibility and FeNO>50 ppb was present in 4% and 8% of workers respectively. Spice-dust-related ocular-nasal (OR 2.40, CI 1.09 to 5.27) and asthma-like (OR 4.15, CI 1.09 to 15.72) symptoms were strongly associated with airborne garlic in the highly exposed (>0.235 μg/m3) workers. Workers monosensitised to garlic were more likely to be exposed to higher airborne chili pepper (>0.92 μg/m3) (OR 11.52, CI 1.17 to 113.11) than garlic allergens (OR 5.08, CI 1.17 to 22.08) in this mill. Probable asthma was also more strongly associated with chili pepper than with garlic sensitisation. Conclusions Exposure to inhalable spice dust (GM >2.06 mg/m3) containing garlic (GM>0.24 μg/m3) and chili pepper (GM >0.44 μg/m3) allergens increase the risk of allergic respiratory disease and asthma.

Yah C.S.,National Institute for Occupational Health NIOH
Biomedical Research (India) | Year: 2013

The rapid emergence of gold nanoparticles (AuNPs) technology holds great promise for future applications due to their large volume specific surface areas with high diverse surface activities than bulk gold. These properties have made AuNPs of great importance in the development of excellent nanoelectronic chips, promising vehicle for a wide range of biomedical and environmental applications. However, the huge impact arising from the physiochemical properties has given rise to new concerns for future health status. Currently, there is dearth information on AuNPs health effects and no regulatory safety and guidelines relating their properties to toxicities. This review, therefore, focuses on the potential toxicological aspect of AuNPs experienced so far and their interactions with biological systems. These can be applied as measures to improve their biomedical applications and risk assessment. However, assessing the safety issues of nanoparticles is quite challenging, because of the vast physiochemical properties that confound their biomedical and toxicological profiles. Therefore more research with standardized NPs physicochemical properties is needed based on the different types of AuNPs to establish both in vitro and in vivo nanotoxicities. The establishment of each size with specific ligand properties will update the complex conflicting ideas emanating from the different AuNPs safety studies thereof.

Van der Walt A.,University of Cape Town | Baatjies R.,University of Cape Town | Baatjies R.,Cape Peninsula University of Technology | Singh T.,National Institute for Occupational Health NIOH | And 2 more authors.
Occupational and Environmental Medicine | Year: 2016

Background This study evaluated the determinants of high fractional exhaled nitric oxide (FeNO; >50 ppb) and serial changes in FeNO over a 24-hour period in spice mill workers at risk of work-related allergic respiratory disease and asthma. Methods A cross-sectional study of 150 workers used European Community Respiratory Health Survey (ECRHS) questionnaires, Phadiatop, serum-specific IgE (garlic, chilli pepper, wheat; Phadia, ImmunoCAP), spirometry and FeNO. A hand-held portable nitric oxide sampling device (NIOX MINO, Aerocrine AB) measured FeNO before and after the 8-hour shift and after 24 hours from baseline. Results The mean age of workers was 33 years; 71% were male, 46% current smokers and 45% atopic. Among workers with garlic sensitisation, 13% were monosensitised and 6% were co-sensitised to chilli pepper. Baseline preshift FeNO geometric mean (GM=14.9 ppb) was similar to the mean change across shift (GM=15.4 ppb) and across the 24-hour period (GM=15.8 ppb). In multivariate linear models, smoking (ß=-0.507) and atopy (ß=0.433) were strongly associated with FeNO. High FeNO (>50 ppb) was significantly associated with asthma-like symptoms due to spice dust (OR=5.38, CI 1.01 to 28.95). Sensitisation to chilli pepper was more strongly correlated with FeNO (r=0.32) and FeNO>50 ppb (OR=17.04, p=0.005) than garlic. FeNO increase (>12%) across 24 hours demonstrated a strong association with elevated exposures to spice dust particulate (OR=3.77, CI 1.01 to 14.24). Conclusions This study suggests that chilli pepper sensitisation is associated with high FeNO (>50 ppb), more strongly compared with garlic, despite the low prevalence of sensitisation to chilli. Elevated inhalant spice dust particulate is associated with a delayed elevation of FeNO across the 24-hour period. © 2016 by the BMJ Publishing Group Ltd.

Makun H.A.,Minna Federal University Of Technology | Makun H.A.,University of Johannesburg | Dutton M.F.,University of Johannesburg | Njobeh P.B.,University of Johannesburg | And 2 more authors.
Journal of Food Safety | Year: 2011

The study reports on the natural occurrence of fungi in 21 samples of field (10), stored (6) and marketed (5) rice (Oryza sativa L.) collected from Niger State, Nigeria. Fungal isolates were primarily identified based on morphological characteristics, while representative isolates were characterized genetically. An evolutionary tree was constructed from the resulting sequences of the isolated fungi. The toxigenic potentials of some of the isolated fungi were also determined. A total of 357 fungal isolates of nine genera including Aspergillus, Fusarium, Sarocladium, Acremonium, Curvularia Botryosphaeria, Penicillium Alternaria and Ascomycota in decreasing order of predominance were identified. The most frequent fungal contaminants of the rice samples were A. flavus, A. fumigates, A. niger, A. parasiticus and F. proliferatum. All strains of A. flavus (aflatoxins B1 and B2), A. parasiticus (aflatoxins B1, B2, G1 and G2), A. ochraceus (ochratoxin A), F. proliferatum and F. verticillioides (fumonisins B1 and B2) tested, were excellent producers of their respective mycotoxins. Patulin was produced by A. terreus, whereas deoxynivalenol, zearalenone and T-2 toxin were produced by F. chlamydosporum and other Fusarium spp. The increased prevalence of toxigenic fungi in rice, a highly consumed food grain in Nigeria, poses serious health concerns to the general public. © 2011 Wiley Periodicals, Inc..

Singh T.,National Institute for Occupational Health NIOH | Singh T.,University of Witwatersrand | Bello B.,National Institute for Occupational Health NIOH | Jeebhay M.F.,University of Cape Town
American Journal of Industrial Medicine | Year: 2013

Background: Exposure in the dental environment can increase the risk of respiratory disease in dental healthcare workers (HCWs). This study investigated the prevalence of asthma phenotypes in dental HCWs and associated risk factors. Methods: A cross-sectional study of 454 dental HCWs in five dental institutions in South Africa was conducted. A self-administered questionnaire elicited the health and employment history of subjects. Sera was analyzed for atopic status and latex sensitization. Pre- and post-bronchodilator spirometry was performed. Results: The prevalence of atopic asthma was 6.9%, non-atopic asthma 5.9% and work-exacerbated asthma (WEA) 4.0%. Atopy and work-related ocular-nasal symptoms were strong predictors of WEA (OR: 3.4; 95% CI: 1.07-10.8; OR: 6.7, 95% CI: 2.4-19.1), respectively. Regular use of personal protective equipment (PPE) was associated with a protective affect (OR: 0.23, 95% CI: 0.1-0.7) among non-atopic asthmatics, while glove use and respiratory protection was protective among atopic asthmatics (OR: 0.39, 95% CI: 0.17-0.89). Conclusion: Identification of risk factors associated with specific asthma phenotypes in dental HCWs can be used to focus preventive strategies for asthmatics. © 2012 Wiley Periodicals, Inc.

Discover hidden collaborations