Water at Hong Kong public housing estates tainted by lead from solder, task force says

Soldering material used on water pipes with a lead content reaching 41 per cent - 585 times the British Standard of 0.07 per cent lead - was the source of contaminated drinking water, a task force investigating the health crisis announced yesterday.

It recommended the Water Authority and Housing Authority step up quality control of all piping, including reviewing relevant legislation, conducting more regular inspections, and centralising the procurement of soldering material. It also called for a change in the soldering method of pipes - such as using compression joints or silver brazing - to avoid lead contamination.

Since the scandal erupted in mid-July, when lead levels above the WHO standard of 10 micrograms per litre were found in the drinking water of Kai Ching Estate, Kowloon City, government tests have unearthed 11 public housing estates, three primary schools, and two kindergartens with excessive lead in water.

At least 139 residents, mostly children under six, from affected estates had lead levels in their blood above the WHO standard of 5 micrograms per decilitre.

"Copper alloy fittings also leach lead but do not result in excessive lead in water," said Dr Chan Hon-fai, a task force member and chairman of the Advisory Committee on Water Resources and Quality of Water Supplies.

"Leaded solder joints are the source of excessive lead in drinking water in Kai Ching Estate and Kwai Luen Estate Phase 2."