Maternal exposure to perfluoroalkyl acids measured in whole blood and birth outcomes in offspring.

Perfluoralkyl and polyfluoralkyl substances have been measured in plasma and serum of pregnant women as a measure of prenatal exposure. Increased concentrations of individual perfluoroalkyl acids (PFAAs), (typically perfluorooctanoic acid (PFOA) and perfluoroctane sulfonate (PFOS) have been reported to be associated with reductions in birth weight and other birth outcomes. We undertook a study of 14 PFAAs in whole blood (including PFOS, PFHxS, PFHpA, PFOA, PFNA, PFDA and PFUnDA) from 98 pregnant women in Western Australia from 2008 to 2011. Median concentrations (in µg/L) were: PFOS 1.99; PFHxS 0.33; PFOA 0.86; PFNA 0.30; PFDA 0.12 and PFUnDA 0.08. Infants born to women with the highest tertile of PFHxS exposure had an increased odds of being <95% of their optimal birth weight (OR 3.5, 95% CI 1.1-11.5). Conversely, maternal blood concentrations of PFUnDA were associated with non-significant increases in average birth weight (+102g, 95% CI -41, 245) and significant increases in proportion of optimal birth weight (+4.7%, 95% CI 0.7, 8.8) per ln-unit change. This study has reported a range of PFAAs in the whole blood of pregnant women and suggests that PFHxS and PFUnDA may influence foetal growth and warrant further attention. Additional studies are required to identify the sources of PFAA exposure with a view to prevention, in addition to further studies investigating the long term health effects of these ubiquitous chemicals.

Maternal exposure to alkali, alkali earth, transition and other metals: Concentrations and predictors of exposure.

Most studies of metals exposure focus on the heavy metals. There are many other metals (the transition, alkali and alkaline earth metals in particular) in common use in electronics, defense industries, emitted via combustion and which are naturally present in the environment, that have received limited attention in terms of human exposure. We analysed samples of whole blood (172), urine (173) and drinking water (172) for antimony, beryllium, bismuth, cesium, gallium, rubidium, silver, strontium, thallium, thorium and vanadium using ICPMS. In general most metals concentrations were low and below the analytical limit of detection with some high concentrations observed. Few factors examined in regression models were shown to influence biological metals concentrations and explained little of the variation. Further study is required to establish the source of metals exposures at the high end of the ranges of concentrations measured and the potential for any adverse health impacts in children.

Investigation of the relationship between low environmental exposure to metals and bone mineral density, bone resorption and renal function.

Environmental exposure to metals has been linked to adverse health outcomes. Exposure to cadmium has been associated with decreased bone density, an increased risk of osteoporotic fracture and possible renal dysfunction. Older women are a group at risk of renal and bone density impacts and exposure to metals may be an important risk factor for these health outcomes. This study was a cross sectional study of 77 women aged 50 years and above examining the relationship between metals exposure and renal and bone health. Urinary and blood metals concentrations, plasma creatinine, iron, ferritin and transferrin were measured in these subjects. Bone biomarkers assessed included the pyridinium crosslinks, pyridinoline and deoxypyridinoline measured by ELISA. Renal function was assessed using eGFR and KIM-1. Whole body, hip and lumbar spine bone mineral density was assessed using DEXA. Blood and urinary metals concentrations were generally low in the subjects, with a median urinary cadmium concentration of 0.26 µg/g creatinine (range <0.065-1.03 µg/g). Urinary cadmium was found to be a significant predictor of bone mineral density at whole body, lumber spine, total hip and femoral neck, with increasing urinary Cd concentrations associated with decreased bone density. Urinary cadmium and aluminium concentrations were positively correlated with bone resorption whilst blood zinc and mercury concentrations were negatively correlated. Urinary aluminium was positively correlated with KIM-1 concentrations, a marker of early kidney damage, however blood zinc concentrations were significantly negatively correlated with this biomarker. This study provides additional support for low cadmium exposure being of concern for the health of older women. Further investigation into the role of exposure to other metals on bone and renal health is warranted.

Polychlorinated biphenyl (PCB) and dioxin concentrations in residential dust of pregnant women.

Polychlorinated biphenyls (PCBs) and dioxins are well known for their persistence in the environment. PCBs can be found in the residential environment long after the use of these chemicals in domestic products and industrial processes has ceased. Dioxins have been assessed in Australia as being of very low concentrations. Despite concerns about residential dust as a source of human exposure to persistent chemicals, there has been limited testing of PCBs and dioxins in dust in Australia. As part of an assessment of maternal exposure to a variety of persistent toxic substances, we analysed 30 residential dust samples from a variety of geographical settings for their dioxin and PCB concentrations. PCBs were found in most samples, the median and range concentrations (pg g(-1)) of dominant congeners of PCB were as follows: PCB118 (315; <35.0-29 000), PCB105 (130; 14.0-16 000) and PCB156 (440; <5.00-2800). Dioxin concentrations were generally low with median concentrations for the total sum of dioxin-like polychlorinated dibenzodioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) of 3.75 pg g(-1) each. There was a very high percentage of non-detects. Concentrations of both PCBs and dioxins were low compared with most studies reporting residential dust concentrations internationally. Age of dwelling was the only factor observed to influence both PCB congener concentrations and dioxin isomers in multivariate regression analyses. No other housing or sociodemographic variables, including proximity to industry, were important predictors in multivariate linear regression models.

Maternal exposure to metals--concentrations and predictors of exposure.

A variety of metals are important for biological function but have also been shown to impact health at elevated concentrations, whereas others have no known biological function. Pregnant women are a vulnerable population and measures to reduce exposure in this group are important. We undertook a study of maternal exposure to the metals, aluminium, arsenic, copper, cobalt, chromium, lithium, manganese, nickel, selenium, tin, uranium and zinc in 173 participants across Western Australia. Each participant provided a whole blood and urine sample, as well as drinking water, residential soil and dust samples and completed a questionnaire. In general the concentrations of metals in all samples were low with the notable exception of uranium (blood U mean 0.07 µg/L, range <0.01-0.25 µg/L; urinary U mean 0.018 µg/g creatinine, range <0.01-0.199 µg/g creatinine). Factors that influenced biological concentrations were consumption of fish which increased urinary arsenic concentrations, hobbies (including mechanics and welding) which increased blood manganese concentrations and iron/folic acid supplement use which was associated with decreased concentrations of aluminium and nickel in urine and manganese in blood. Environmental concentrations of aluminium, copper and lithium were found to influence biological concentrations, but this was not the case for other environmental metals concentrations. Further work is underway to explore the influence of diet on biological metals concentrations in more detail. The high concentrations of uranium require further investigation.

Cadmium, lead and mercury exposure in non smoking pregnant women.

Recent literature suggests that exposure to low concentrations of heavy metals may affect both maternal and child health. This study aimed to determine the biological heavy metals concentrations of pregnant women as well as environmental and dietary factors that may influence exposure concentrations. One hundred and seventy three pregnant women were recruited from Western Australia, each providing a sample of blood, first morning void urine, residential soil, dust and drinking water samples. Participants also completed a questionnaire which included a food frequency component. All biological and environmental samples were analysed for heavy metals using ICP-MS. Biological and environmental concentrations of lead and mercury were generally low (Median Pb Drinking Water (DW) 0.04 µg/L; Pb soil <3.0 µg/g; Pb dust 16.5 µg/g; Pb blood 3.67 µg/L; Pb urine 0.55; µg/L Hg DW <0.03; Hg soil <1.0 µg/g; Hg dust <1.0 µg/g; Hg blood 0.46 µg/L; Hg urine <0.40 µg/L). Cadmium concentrations were low in environmental samples (Median CdDW 0.02 µg/L; Cdsoil <0.30 ug/g; Cddust <0.30) but elevated in urine samples (Median 0.55 µg/L, creatinine corrected 0.70 µg/g (range <0.2-7.06 µg/g creatinine) compared with other studies of pregnant women. Predictors of increased biological metals concentrations in regression models for blood cadmium were residing in the Great Southern region of Western Australia and not using iron/folic acid supplements and for urinary cadmium was having lower household annual income. However, these factors explained little of the variation in respective biological metals concentrations. The importance of establishing factors that influence low human exposure concentrations is becoming critical in efforts to reduce exposures and hence the potential for adverse health effects.