Environmentalists have called for a reduction in emissions of the toxic chemicals dioxins in Wales.

Their demand follows a leaked report from America's official environment watchdog which said one type of dioxin can cause human cancer.

There has long been a debate about whether dioxins are carcinogenic.

The chemicals can be created as a by-product of heavy industry, bonfires and fireworks.

The highest industrial emissions in Wales come from the former British Steel plant at Llanwern near Newport.

In a leaked report the Environmental Protection Agency in America said for the first time that one type of dioxin can cause human cancer.

Emissions of dioxins have plummeted since the 1970s.

Heavily regulated

According to the Environment Agency, the steel works in LLanwern near Newport had the highest levels in England and Wales last year when it came to industrial emissions of dioxins into the environment

Although the levels of the most toxic dioxin referred to in the leaked report as a human carcinogen are extremely small.

And the plant is heavily regulated and meets all the requirements laid down by law.

The Environment Agency said the levels in the area around Llanwern are the same as any other similar area.

The company which runs the former British Steel plants - Corus - said last year it reduced dioxin emissions from its plants by 10% and hopes to do so further.