Accidents, illness, strangers: danger to children takes many forms. But, for brain damage caused by toxic mining metals, the streets closest to the mines in Broken Hill, Mount Isa and Port Pirie must rank as the most dangerous in Australia.
Children in these mining and smelting cities exposed to high levels of lead, arsenic and cadmium are more than twice as likely to have developmental delays than the national average, new research shows. 
These children are at a much higher than average risk of lifelong neurobehavioural deficits. And those who live closest to the mines are at highest risk.
"It basically tells you the closer you live to the line of lode, the worse off you are," said Mark Taylor, professor of environmental science at Macquarie University who led the study published this week in the journal Environmental Pollution.
In the first known such use of NAPLAN data, the researchers took the NAPLAN results of children in school catchment areas known to have high levels of toxic metals in the environment and compared them with those of their peers around the country.
They found the children living closest to Broken Hill's lead and zinc mine - where exposure levels to toxic air, dust and soils are highest - consistently had the lowest literacy and numeracy scores in years three and five.
In Australia's two other lead mining and smelting cities, Mount Isa in Queensland and Port Pirie in South Australia, the results were similar.
The researchers also looked at Australian Early Development Census (AEDC) data, which assess children in their first year of school for physical health and wellbeing, social competence, emotional maturity, language and cognitive skills, communication skills and general knowledge.
Children from the two Broken Hill school catchments with the highest environmental contamination were 2.6 times more likely to have vulnerabilities in two or more of the AEDC developmental areas.
After adjusting for socio-economic disadvantage, the difference between children attending schools with the maximum soil lead risks compared with the lower soil lead risk areas was about 60 NAPLAN points, or about 14 per cent.
Lead is a neurotoxin, which can affect the development of a child's nervous system if it is absorbed, inhaled or ingested.
Its effects are greatest in unborn children and those aged up to five, because the nervous and skeletal systems need high levels of calcium to develop properly. The bodies of children growing up in lead-rich environments can be tricked into absorbing lead instead of calcium, which lead mimics.
A blood testing program in Broken Hill between 1991 and 2009 showed declining lead levels, but since 2010 they have headed upwards.
In   May this year the National Health and Medical Research Council halved the blood lead level at which health intervention is required from 10 to five micrograms per litre.
This means about half the children under five in Broken Hill require health intervention for excess dangerous levels of lead in their blood.
Andrew Pressler of Broken Hill manages a business that has recently been accredited in the machine extraction of lead from dust, for example from ceilings and gutters of houses.
He had his own children tested and was relieved to learn "they have not been affected" by lead in the environment.
Mr Pressler said it was a "very sensitive issue" in the city. While people were "fully aware" of the problem, they tend to "forget about it".
"We really need to come back to the tasks" to lower the risks, Mr Pressler said.
Professor Taylor said this meant stopping children from playing in the dirt (which could mean astroturfing their yards), frequent hand washing, keeping shoes and pets outside, keeping windows closed and ripping up old carpets, with bare floorboards a preferable option.
He said families should get their children's blood tested. "It is really important that they stay on top of the risks and do everything they can to mitigate them," he said.
"These are subtle changes but when you add up the total sum of [them] for the whole community, and all the lost IQ points, that is quite a lot.
Professor Taylor said said a typical adult response was, "There is nothing wrong with me and I have lived here all my life."
While some people may find it easier to ignore the study's findings, "there is an opportunity to protect children into the future".
The companies, too, needed to work hard to reduce emissions, he said.
"It needs to be a whole of community effort. What this information does is confirms that intervention programs that have been implemented are really important."
The NSW government is spending $13 million on a five-year program to address the issue of elevated blood lead levels among Broken Hill children.
Hundreds of millions of dollars are being spent by the mining companies in both Mount Isa and Port Pirie to mitigate contamination.