For example, the length of time a mother breastfeeds increases as the mother's level of education increases. Married mothers tend to breastfeed for longer periods than those who are not currently married. In addition, Indigenous mothers and older mothers tend to breastfeed their children for longer periods than non-Indigenous mothers and younger mothers. Over the past 20 years there has been increasing community awareness about the quality of the environment and its effect on children's health. In particular, attention has focused on the effects of lead on the mental development of children aged under four years.
Young children tend to have the highest blood lead levels of any age group.
Lead in petrol is a significant source of environmental lead, but deteriorating lead-based paint is considered the most dangerous source of lead exposure. Other possible sources of lead in the environment are lead in the solder of canned acidic foods, lead released from lead smelters and passively-inhaled cigarette smoke. Government initiatives to reduce lead levels in the environment include the use of unleaded petrol in Australian vehicles purchased since 1986 and a reduction in the levels of lead in paint. The National Survey of Lead in Children was conducted in 1995 of children aged 1-4 years. The mean blood lead level was higher among younger children and decreased with age.