Greenpeace said Tuesday that the world's most popular electronic game consoles contain high levels of toxic chemicals, though they do not pose an immediate danger to gamers.
A report by the environmental watchdog group said Nintendo's Wii, the Sony Playstation 3 and Microsoft's Xbox 360 use varying degrees of bromine, PVCs and other potentially harmful chemicals, including phthalates, which can affect human hormones.
Greenpeace acknowledged the level of toxic material did not violate European regulations, although some are banned from use in toys meant for small children.
Though not harmful in the amounts used, some chemicals are released into household dust, inhaled and pile up in the body over time.
"Nobody will drop dead tomorrow," said Greenpeace campaigner Zeina AlHajj. "But these products are used by kids. ... They are persistent and they are accumulating through our life."
In response to the report, Nintendo said it requires its suppliers to certify their parts contain no hazardous substances and that its products comply with global standards.
"Nintendo is always actively looking at ways to continue to increase its environmental stewardship and holds this as a corporate priority worldwide," it said in a statement.
Microsoft has said in response to earlier Greenpeace criticism that it is "committed to making ongoing progress on environmental issues while ensuring our continued commitment to product durability, safety and performance."
Greenpeace said some consoles made by the three companies use chemicals that others avoid or use in small amounts, meaning that each of them could easily produce safe products.
Nintendo, for example, does not use beryllium alloys in its electrical contacts, while Microsoft and Sony do.
The Playstation 3 uses bromine-free circuit boards, and Xbox 360 had lower levels of brominated materials than the others, the report said.
Greenpeace said the three companies have pledged to phase out toxic chemicals within a few years, but urged them to move faster.
"Our campaign focuses on challenging the electronics industry to go beyond legislation," AlHajj said.
The machines are most dangerous, Greenpeace said, after they have been thrown away and become electronic waste.
They join hundreds of thousands of mobile phones, outdated computers and other electronic goods dumped into landfills or burned in smelters, from where toxic chemicals can seep into the environment, the group said.
Many products are shipped to developing countries where they are haphazardly dismantled, Greenpeace said.
The Amsterdam-based environmental agency began in 2006 to produce quarterly reports ranking the top 18 consumer electronics companies on their plans to reduce hazardous components, their transparency and their takeback and disposal policies.
Nintendo, which entered the list last year, ranks last; Microsoft is not far ahead; while Sony is in the upper quarter.