The cause was paint dust from her bedroom ceiling.

Dust inside old houses is also a threat because it often contains flaking paint dust.

A fine cloud of paint dust lifted off the door and floated down to the ground.

But because children between 15 months and 6 years old can ingest large amounts of lead from paint dust or chips, the problem remains large.

Children also have frequent hand-to-mouth contact, so placing their hands in paint dust may be enough to introduce significant toxicity into their systems.

Hang plastic sheets over the doorways of rooms where work is being done to minimize the spread of paint dust.

There is no studio to visit, no paint dust on his trousers.

"You can get it by inhaling paint dust, which could come from just opening and closing the window," she said.

There are many sources of lead exposure, including paint, dust and industrial waste and emissions.

It can cause brain damage when paint chips are swallowed or when paint dust is inhaled.