But their presence, contributing to the environmentally risky content of incinerator by-products and the liquid “leachate” that trickles out of landfill sites, is a significant headache.

The garage, basement and cupboards of the average US home stores as much as 45 kilograms of household hazardous waste (HHW), including solvents, adhesives, some cosmetics, polishes, oven cleaners, motor oil, pesticides, fertilizers, swimming pool chemicals, art supplies and pharmaceuticals.

Batteries are the main sources of heavy metals, particularly lead, mercury and cadmium in US municipal waste. Exposure to these can damage organs such as the liver, kidneys, lungs, nervous system and brain.

FACTS Breakdown of US hazardous waste Household maintenance items (paints, solvents, adhesives) 36.6% Household batteries 18.6% Cosmetics (inc nail polish & removers) 12.1% Cleaners (inc polishes, oven cleaners) 11.5% Automotive items (mostly motor oil) 10.5% Garden items (inc pesticides, fertilizers) 4.1% Hobby (pool chemicals, art supplies) 3.4% Pharmaceuticals 3.2% Source: ISWA WGHW

The amount of mercury in US waste has dropped to slightly more than a quarter of its 1989 level following moves to eliminate the metal from batteries. But the amount of lead in the nation’s rubbish has continued to rise, with consumer electronics now contributing 30% of the lead in the waste stream, compared to only 7% in 1970. Cadmium has also risen, although mobile phone manufacturers are increasingly rejecting nickel-cadmium batteries for lighter lithium-ion ones.

Fluorescent tube lights also contain heavy metals, making electric lighting responsible for 26% of the mercury found in America’s municipal waste. The UK charity Wastewatch says a typical 1.2 metre fluorescent tube contains enough mercury to pollute 30,000 litres of water above the European Community’s recognised safe-to-drink level.

Used televisions have been classed as hazardous waste in the UK, because of the heavy metals they contain.

Single-day collections for hazardous items and some permanent collection points were set up across the US in a drive to tackle household hazardous waste during the 1980s. Three thousand programmes had been established by 1997.