Domestic consumption makes up the majority (up to 85 percent) of waste electronic and electrical equipment (WEEE) produced in the region, according to the study, Where are WEEE in Africa?

The e-waste problem in West Africa is further exacerbated by an ongoing stream of used equipment from industrialised countries, significant volumes of which prove unsuitable for re-use and contribute further to the amount of e-waste generated locally.

In the five countries studied in the UN report (Benin, Côte d'Ivoire, Ghana, Liberia, and Nigeria), between 650,000 and 1,000,000 tonnes of domestic e-waste are generated each year, which need to be managed to protect human health and the environment in the region.

Where are WEEE in Africa? sheds light on current recycling practices and on socio-economic characteristics of the e-waste sector in West Africa. It also provides the quantitative data on the use, import and disposal of electronic and electrical equipment in the region.

The report draws on the findings of national e-waste assessments carried out in the five countries from 2009 to 2011.

Download the report 

The authors, led by Alex Lu, associate professor of environmental exposure biology in the Department of Environmental Health, write that the new research provides "convincing evidence" of the link between imidacloprid and the phenomenon known as Colony Collapse Disorder (CCD), in which adult bees abandon their hives.

The study will appear in the June issue of the Bulletin of Insectology.

"The significance of bees to agriculture cannot be underestimated," says Lu. "And it apparently doesn't take much of the pesticide to affect the bees. Our experiment included pesticide amounts below what is normally present in the environment."

Pinpointing the cause of the problem is crucial because bees-beyond producing honey-are prime pollinators of roughly one-third of the crop species in the U.S., including fruits, vegetables, nuts, and livestock feed such as alfalfa and clover. Massive loss of honeybees could result in billions of dollars in agricultural losses, experts estimate.

Lu and his co-authors hypothesized that the uptick in CCD resulted from the presence of imidacloprid, a neonicotinoid introduced in the early 1990s. Bees can be exposed in two ways: through nectar from plants or through high-fructose corn syrup beekeepers use to feed their bees. (Since most U.S.-grown corn has been treated with imidacloprid, it's also found in corn syrup.)

In the summer of 2010, the researchers conducted an in situ study in Worcester County, Mass. aimed at replicating how imidacloprid may have caused the CCD outbreak. Over a 23-week period, they monitored bees in four different bee yards; each yard had four hives treated with different levels of imidacloprid and one control hive. After 12 weeks of imidacloprid dosing, all the bees were alive. But after 23 weeks, 15 out of 16 of the imidacloprid-treated hives-94%-had died. Those exposed to the highest levels of the pesticide died first.

The characteristics of the dead hives were consistent with CCD, said Lu; the hives were empty except for food stores, some pollen, and young bees, with few dead bees nearby. When other conditions cause hive collapse-such as disease or pests-many dead bees are typically found inside and outside the affected hives.

Strikingly, said Lu, it took only low levels of imidacloprid to cause hive collapse-less than what is typically used in crops or in areas where bees forage.

Scientists, policymakers, farmers, and beekeepers, alarmed at the sudden losses of between 30% and 90% of honeybee colonies since 2006, have posed numerous theories as to the cause of the collapse, such as pests, disease, pesticides, migratory beekeeping, or some combination of these factors.