How Can Birth Cohort Studies Contribute to Knowledge and Policies of the World to Reduce Risks of Emerging Contaminants?

摘要

A number of epidemiologic studies have revealed the environment can affect child health and development. Exposure to specific chemical substances during foetal and early childhood may cause health problems in later life. Children have unique exposure characteristics such as specific routes of exposure (e.g. through placenta and breastfeeding), exploratory behaviours (e.g. hand-to-mouth, object-to-mouth, pre-ambulatory and high-risk behaviours) and specific physiology (e.g. high oxygen demand, high breathing rate, low stature and high surface area to volume ratio). Understanding how children expose to harmful environment qualitatively and quantitatively and how the exposure associates with child health and development is essential for children's environmental health. Contaminants of emerging concern (CECs) in human health context are groups of chemical substances that existed in the past but with new concern and that are introduced to market recently and concerned to have potentially harmful effects. For example, lead is a legacy contaminant but has posed new concern about its effect on child neurological development at relatively low exposure. Particulate matter is not a single chemical but a long-lasting pollutant that appears to affect children's lung function at low level exposure. Algal toxins are another legacy group of chemicals with new health concern. Examples of newly introduced chemicals include pesticides, pharmaceuticals and personal care products, fragrances, plasticisers, hormones, flame retardants, nanoparticles, poly- and perfluoroalkyl compounds, chlorinated paraffins, siloxanes and various trace elements including rare earths. To better characterise the effect of the CECs on child health and development, many researches have been initiated in Asian countries as well as North America and Europe. Some studies look at a single to few CECs and others do many CECs simultaneously. Some studies characterise foetal exposure and others start from birth. Some studies evaluate health outcomes in trajectory, e.g. growth curves and changes in developmental scores. Some uses advance statistical methodologies to analyse the effect of multiple contaminants that potentially correlate each other. In this presentation, a potential of birth cohort studies on addressing risks of CECs will be discussed.