SA Health data shows Port Pirie lead levels are some of the highest on record.

Lead levels in Port Pirie two-year-olds have hit the highest level recorded since the testing regime began in 2011.

Two-year-olds are considered the most accurate age group to measure lead exposure in the general population.

The proportion of children with blood lead levels above 5 mcg/dL (which national guidelines say should trigger further investigation) has increased in the last year. The number of blood lead levels below 10 mcg/dL also increased.

However, there has been a reduction in the number of children tested showing lead levels equal to or above 20 mcg/dL.

“The improvements or deteriorations in all other reported measures were slight — indicating that blood lead trends have generally stalled over the past 12 months,” says SA Health Director of Scientific Services David Simon

Dr Simon pointed to “extended periods of time when smelter operations were shut down” in 2019 as a partial explanation of the results.

“Changes in lead-in-air do not have an immediate impact on population blood-lead levels and there are a number of different factors that contribute to changes in a child's blood-lead levels,” he said.

“It takes time for blood-lead levels to decrease after lead exposure has reduced, and a child's age, where they live, their behaviour, and what they eat can all play a part.”

Nystar operates Port Pirie's lead smelter, and has spent over $350 million installing cleaner technology intended to halve the operation's lead emissions.

But lead-in-air readings for the latest quarter have been increasing throughout the year.

SA’s Environmental Protection Authority recently slashed the company's allowable annual lead emissions, and reports say it has managed to keep below its new emission limits.