A new study focused on the remote mining town of Broken Hill in New South Wales, Australia, has found a pattern of poor academic performance by children in areas contaminated by toxic mining chemicals.

The study carried out by researchers from Macquarie University in Sydney found that children in the mining town exposed to lead, arsenic and cadmium contaminants may have issues with two or more areas of development.

Macquarie University environmental science professor Mark Taylor told ABC that better grades were scored by students from districts having low levels of heavy metals in the environment.

Taylor said: "The difference between children attending schools in areas with the maximum soil lead risks compared to the lower soil lead risk is 20 NAPLAN points, or about 5%."

"Better grades were scored by students from districts having low levels of heavy metals in the environment."

The authors reviewed data on air pollution in six different areas of Broken Hill by collecting soil samples.

As part of the study published in the journal Environmental Pollution, the Australian Early Development Census (AEDC) data was also considered by the authors.

Taylor said the data, obtained through the combination of AEDC, National Assessment Program – Literacy and Numeracy (NAPLAN) and environment statistics, shows metal contamination of the urban environment contributes to blood lead exposures, affecting academic performances.

Children living close to Broken Hill’s lead and zinc mine were highly exposed to toxic air, dust and soils consistently and exhibited the lowest literacy and numeracy scores.

The study also found similar results in lead mining and smelting cities Mount Isa and Port Pirie.

Children exposed to dangerous levels of lead and other toxic chemicals have an increased risk of developmental disorders.