Australian children and adults exposure to trace elements, and their association with cognition and development

Australian children and adults are potentially exposed to a range of trace elements through their food intake and physical environments. Some elements, such as iron, copper and iodine, are vial trace elements for life; with deficiency causing illness and high levels being toxic. Others, such as lead and mercury, are thought to only be toxic – these have been associated with diverse developmental outcomes, including anti-social behaviour, body mass index, depression and impulsivity. There is little known about the patterns of element exposure in Australian children and adults (e.g. does exposures to heavy metals cluster together?), and if exposure to metal mixtures amplify neurotoxicity compared to exposure to a single element.

The Longitudinal Study of Australian Children (LSAC) is a national, population-derived cohort assessing children and their families every two years since birth. These biennial assessments include interview, questionnaire and computer-based testing of cognition and physical development. In 2015-16, children (aged 11-12 years) and one of their parents completed a physical health assessment and biospecimens module, called the Child Health CheckPoint. Urine samples collected from the approximately 2000 children and 2000 parents at the CheckPoint visit are currently being analysed for 75 elements, and data are expected to be available prior to the beginning of the student project. Other physical health measures collected at the CheckPoint assessment include body composition; cardiovascular and respiratory health; musculoskeletal, renal, hearing and visual characteristics; physical activity and sleep, allergies and pain.

We propose to work with an Honours student to investigate patterns of Australian children and adults exposure to trace elements, and how beneficial and toxic elements (are associated with cognition and development. There is latitude in this project for the student to select which cognitive and development outcomes are of interest to investigate, given the broad range of outcome data available.

Children can be exposed throughout childhood to beneficial and toxic elements (trace metals and non-metals) through their food intake and physical environments, although at lower levels than children in less developed nations. Lead and mercury exposure are associated with diverse developmental outcomes, including anti-social behaviour, body mass index, depression and impulsivity. Recent research has implicated cadmium and manganese in poorer cognition and behaviour. There is little known about the interactive effect of metal mixtures, and if the work together to amplify neurotoxicity compared to exposure to a single element.  The Longitudinal Study of Australian Children (LSAC) is a national, population-derived cohort assessing children and their families every two years since birth. Child cognition and physical development are measured every two years. At age 11-12 years, study participants completed a physical health assessment and biospecimens module, called the Child Health CheckPoint. Urine samples collected from the approximately 2000 study children at the CheckPoint visit are currently being analysed for 75 elements, and data are expected to be available prior to the beginning of the student project. Other physical health measures collected at child age 11-12 years include body composition; cardiovascular and respiratory health; musculoskeletal, renal, hearing and visual characteristics; physical activity and sleep, allergies and pain.

We propose to work with an Honours student to investigate how beneficial and toxic elements (trace metals and non-metals) are associated with children's cognition and development. There is latitude in this project for the student to select which cognitive and development outcomes are of interest to investigate, given the broad range of outcome data available.