10 things Hongkongers need to know about lead-contaminated water

A scandal involving unusually high levels of lead in three public housing estates has got the whole of Hong Kong talking. The Society of Hospital Pharmacists of Hong Kong has listed 10 frequently asked questions in light of the tainted water scare.

Q: Can lead be absorbed and accumulated in the body after one drinks water containing lead?

A: Part of the lead would be absorbed by the body after taking food or water containing lead. Adults absorb 10 per cent, while children absorb between 30 and 50 per cent. Lead that has not been absorbed would be excreted.

It takes around 30 days for lead levels in one’s blood to be reduced by half. Lead is carried by one’s blood to different tissues and organs, and around 90 per cent of lead (70 per cent for children) stays in one’s bones and teeth. It takes a long time for lead levels in one’s bones to be reduced, and the lead would gradually be released into one’s blood. Hence it is still possible for lead to appear in one’s blood even after ceasing consumption of water with lead. That said, the harm is small if lead stays in one’s blood.

Q: How does lead exist in water? What dietary recommendations, if any, are there to flush lead out of the body?

A: Lead can take on soluble or insoluble form in water. At present no international organisations have determined that drinking more water can hasten the flushing of lead out of the body.