Article – Science Media Centre
Lead’s lingering effects
Lead exposure in childhood was linked to lower cognitive function, IQ and socioeconomic status, according to data from the Dunedin Study.
The study, published this week in JAMA, used data from the longitudinal study, which has been tracking a cohort of 1,000 participants born in Dunedin in 1972 and 1973.
Of the participants still alive at age 38, about half had been tested for lead when they were 11 years old.
High blood-lead levels were found in children from all socioeconomic levels, indicating the exposure was from leaded petrol fumes spread across all communities evenly – as opposed to lead pipes or leaded paint, which pose more of a threat to disadvantaged families.
By age 38, those study participants with high childhood lead levels had IQs, on average, 4.25 points lower than their peers and they were found to have lost IQ points relative to their own childhood scores. They were also in jobs of a lower socioeconomic status than their parents.
Dunedin Study associate director Professor Terrie Moffitt said the data came from an era when high lead levels were seen as normal for children.
“This research shows how far-sighted New Zealand was when the country banned leaded petrol in 1996.”
“Lead exposure is very rare in Kiwi children today. But the findings suggest the importance of keeping up our vigilance against other environmental pollutants.”
University of Otago public health researcher Dr Nick Wilson told the Otago Daily Times that the oil industry should take some of the blame for the damage caused, suggesting that there was deliberate lobbying by industry against removing lead additives from petrol.
Atmospheric lead peaks in winter
GNS Science said this week that lead fumes in urban air may still present an exposure risk.
Air monitoring work has found atmospheric conditions of lead peak during winter in New Zealand urban centres, possibly due to burning of old painted timber.
Study leader Dr Perry Davy said the peaks didn’t always coincide with the coldest weather, suggesting some of the burning is “opportunistic”.
“These studies show that air in New Zealand urban centres is not as clean as we would like to think.”
“We have no idea what the concentration might be inside the home or in the neighbourhood of someone burning this stuff,” Dr Davy told stuff.co.nz.