Dandora is far and away the largest refuse dump in the 4.5-million-strong Kenyan capital, and with 2,000 tons of fresh waste every day, it also holds the dubious distinction of being a member of the "dirty 30" club of the world's most polluted sites.
According to a 2007 report by the Blacksmith Institute, the festering eyesore on the outskirts of the city is one of the two most polluted sites on the continent, the other being a lead mine in Zambia.
"Every time the dump spews a large cloud of smoke, I start coughing," says Priscilla, whose Saint John school in Korogocho slum is often shrouded in a cloud of thick noxious fumes.
Her blood lead level is 19.9 microgrammes per decilitre, twice the international norm.
Kenya prides itself on progressive measures to protect the environment, a major asset in its lucrative tourism industry, which attracts millions of visitors each year.
Yet Dandora's 75 acres of fuming waste -- a sea of plastic bags, used medical supplies, car batteries, dismantled printers and computers -- is a blot in the picture that is causing growing concern.
"Electronic waste contains a lot of lead and also mercury and cadmium (that) cause multiple toxic problems," said Njoroge Kimani, a biochemist who authored a report commissioned by the United Nations Environment Programme (UNEP).
"Children can get lead from inhaling the fumes, from picking objects from the ground, from the dust of the wastes on vegetables," the Kenyan expert added.
A new trend which sees developed nations dump e-waste -- costly to treat or recycle -- has been allowed to develop in the vacuum left by the Kenyan authorities, environmental officials warn.
"We already have evidence of Africa generally being used as a dump site for electronic waste with very heavy metals in them," UNEP Executive Director Achim Steiner told reporters recently.
"Right now ... we see the emergence of e-waste being dumped here in Kenya," he added.
He said dumping was often carried out under the guise of schemes claiming to donate second-hand computers to Africa. Up to a quarter of the 'donations' are in fact unusable and are subsequently dumped in the recipient country.
According to UNEP, between 20 to 50 million metric tonnes of e-waste are produced globally each year, much of which finds its way to the African continent as charitable donations.
"Dump sites are poisoners if not handled properly," Steiner stressed.
Environmentalists, health officials and NGOs are concerned at the absence of waste management in Kenya, whose developing economy is witnessing an exponential boom in electronic production.
The African country worst affected by e-waste is believed to be Nigeria but Richard Kiaka Dimba, from the Eco-Ethics International, says the problem was spreading.
"We are anticipating that in the near future there will be a crisis" in Kenya, he told AFP. "These foreign countries are exploiting the weaknesses of environmental instruments in Kenya."
A study carried out by Dimba earlier this year revealed that 10 to 20 percent of the computers sent to Kenya each year -- mainly from the United States and United Kingdom -- are unusable.
"There are too many computers coming ... There is a saturation and there's no system to handle e-waste" in the country, said Tom Musili, executive director of Computers for Schools Kenya.
He said his NGO was in the process of shipping back unusable computers to donor countries in a bid to counter the dumping phenomenon.
Benjamin Langwen, in charge of compliance and enforcement on environmental issues at the state-run National Environment Management Authority, conceded that Kenya had little infrastructure to deal with e-waste.
"It's going to be a major problem in future," he told AFP. "The state of industrial, electronic and solid waste management is not good enough."
Computer donations "are giving us more problems", Langwen argued, and "cause an enormous impact on environment in Kenya... It will cost the country a lot of money, even more that the donation given."
John Kilonzi, a 19-year-old scavenger from Dandora, dismisses the health hazard posed by e-waste for he has a more pressing goal: finding something to eat amidst the rubbish, or at least something that will pay for it.
"We can't say it's dangerous because it's where we get our food."