In vitro assessment of the toxicity of bushfire emissions: A review.

Bushfires produce many toxic pollutants and the smoke has been shown to have negative effects on human health, especially to the respiratory system. Bushfires are predicted to increase in size and frequency, leading to a greater incidence of smoke and impacts. While there are many epidemiological studies of the potential impact on populations, there are few studies using in vitro methods to investigate the biological effects of bushfire emissions to better understand its toxicity and significance. This review focused on the literature pertaining to in vitro toxicity testing to determine the state of knowledge on current methods and findings on the impacts of bushfire smoke. There was a considerable variation in the experimental conditions, outcomes and test concentrations used by researchers using in vitro methods. Of the studies reviewed, most reported adverse impacts of particulate matter (PM) on cytotoxic and genotoxic responses. Studies on whole smoke were rare. Finer primary particulates from bushfire smoke were generally found to be more toxic than the coarse particulates and the toxicological endpoints of bushfire PM different to ambient PM. However the variation in study designs and experimental conditions made comparisons difficult. This review highlights the need for standard protocols to enable appropriate comparisons between studies to be undertaken including the assessment of physiologically relevant outcomes. Further work is essential to establish the effect of burning different vegetation types and combustion conditions on the toxicity of bushfire emissions to better inform both health and response agencies on the significance of smoke from bushfires.

Metals in commonly eaten groceries in Western Australia: a market basket survey and dietary assessment.

Children's dietary exposure to metals has received limited attention in Australia. This study undertook a market basket survey and analysed 253 food and beverages for metals. These data were used in conjunction with recent average diet data for children in Western Australia to model dietary metals exposure, with mean metals intakes calculated for boys and girls aged 8, 12, 13 and 16 years. Results show that for some metals, including cadmium, nickel and manganese, dietary intake guidelines have been exceeded in younger children. The mean modelled cadmium intake in children aged 8 years was almost 60% of the World Health Organisation (WHO) guideline and exceeded the European Food Safety Authority (EFSA) guideline. Nickel and manganese intake was higher in younger children than reported in international studies. Modelling based on the 95% percentile of dietary consumption exceeded the respective guidelines or upper level of intake for several of the metals studied. The findings from this study support the need for further investigation into the exposure of children to metals from diet and the health implications of exposure.

Estimating maternal and prenatal exposure to glyphosate in the community setting.

Glyphosate is a herbicide in common use, in both agricultural and residential settings. Controlled residue studies show that glyphosate persists in food crops, allowing for the potential of a large number of people to be exposed. Glyphosate is generally considered safe however there are a number of studies suggesting formulations or additives that may have adverse health effects. To assess the degree of exposure of pregnant women, this study measured glyphosate in composite food samples and estimated exposure based on food frequency questionnaire. 43 pregnant women were recruited and completed a self administered questionnaire with a food frequency component and provided a composite food sample. Twenty food samples were analysed with very low glyphosate concentrations (mean 0.08 mg/kg, range 0.002-0.5 mg/kg) with residues detected in more than 75% of the samples. Maternal dietary exposure was very low (0.001 mg/kg bw/day) and was considerably lower than the predicted National Estimated Daily Intake of glyphosate (0.02 mg/kg bw/day). The estimated exposure based on measured glyphosate in composite food samples corresponded to 0.4% of the acceptable daily intake for glyphosate, and the predicted concentration from dietary information was 4% which is comparable to the National Estimated Daily Intake of 5.5% of the Acceptable Daily Intake of glyphosate. Prenatal exposures were estimated to be significantly lower. While residues of glyphosate are present in food, this study demonstrates that exposure concentrations are low and confirms the current models used to estimate glyphosate exposure.