Outdoor cremations were banned in 1930, mainly because of fears that dental fillings containing mercury would release dangerous emissions into the atmosphere.

ECONOMIST: Cremation: Up in flames | The

The prosecution said she put mercury amalgam - a substance used in dental fillings - into a cup of coffee she made for Ms Knowles, but the defendant claimed she was set up by her co-workers.

BBC: 'Mercury coffee' case accused to face retrial

Promotions for chelation are combined with warnings about lead-contaminated toys and mercury in coal-plant emissions, fish and dental fillings.

FORBES: Health

The government says mercury is not a health risk, although it does advise against dental treatment in pregnant women.

BBC: Dentist