Port Pirie smelter shutdown contains lead levels

Drastic action by the operator of a South Australian lead smelter has averted a breach of its licence conditions.

The Nyrstar smelter at Port Pirie, South Australia.

Drastic action by the international operator of a lead smelter in South Australia to ­reduce dangerous emissions has averted a breach of its licence conditions.

The latest lead-in-air test ­results for the industrial city of Port Pirie, 230km north of Adelaide, are at five-year highs, ­according to Environmental Protection Authority data, but remain under the limit after Belgian ­metals company Nyrstar shut down parts of its operation late last year.

At the end of each quarter, Nyrstar must meet a rolling 12-month average of lead-in-air ­levels below 0.5 micrograms per cubic metre at two compliance sites in Port Pirie. The December quarter readings of 0.49 and 0.48 micrograms continued a rising trend that started in 2015 — around the time work on a $660 million smelter upgrade started — when levels hovered around 0.2 micrograms.

Nyrstar said it would continue to enact similar measures that saw the monthly December reading at both compliance sites come in at 0.14 micrograms.

These measures included re­directing some of its 700-strong workforce away from normal ­duties to cleaning up the Port Pirie site, which is laden with fine lead dust that is carried into the community by wind.

Key parts of the smelter were also shut down intermittently and replaced by “environmental ­activities”. “The high result in 2018 was a consequence of short-term dust sources during the commissioning of a new plant in combination with the ongoing operation of the sinter plant,” a Nyrstar spokeswoman said.

Other significant emission sources included dust from feed material stockpiles and blast furnaces, the spokeswoman said.

Childhood exposure to lead has been linked to lower IQ and academic achievement, and to a range of socio-behavioural problems such as attention deficit ­hyperactivity disorder and learning difficulties.

SA Health regularly tests Port Pirie children aged five and under. Its results from the September quarter found 12 children at high risk of health effects with blood-lead levels above 20 micrograms per decilitre, compared with seven a year earlier. The average blood-lead level for children tested at two — when brain development is at its most crucial stage — had also increased to 5.8 micrograms. A reading greater than 5 micro­grams suggests a person has been exposed to lead at a level that could be harmful.