Zero Waste: Article on mercury

From Zero Waste New Zealand: UPDATE JULY 2006

More on mercury

Since our last write-up on the hazards of mercury, I have been reminded that mercury use is even more widespread in its use than I had imagined. Here’s a new list of mercury-containing items:

• fluorescent light bulbs – the regular 5’ and 6’ tubes often used in shops and offices
• the new, energy-saving compact light bulb - great, but still a fluorescent bulb with mercury
• FL and HID lamps, used in high powered projectors (for screening your DVDs, perhaps)
• mercury switches for boot lighting (when the boot lid door opens)
• antilock braking systems
• air bag switches
• active-ride control switches
• some thermometers
• amalgam for tooth fillings
• alkaline and button batteries - the single largest source of mercury in our household rubbish

Exposure to mercury compounds can cause serious human health and ecological effects. When mercury-containing products become broken and are exposed to moisture from rain or groundwater, they leak mercury into the environment. Once deposited, micro-organisms can change the mercury into methyl-mercury, a highly toxic and volatile compound that can move through the air, soil and water. It builds up in seafood, and in the animals and people that eat the seafood. Even in remote areas, animals and people are being found to have elevated mercury levels.

Here in New Zealand, we are doing very little to address this issue of mercury pollution, apart from warning pregnant women that they should avoid eating some species of fish. The problem is much greater than this, as very few of the items on the above list are properly handled for disposal.

The vast majority of these items (98% plus) are indiscriminately handled and casually disposed of into landfill, with breakages and contamination prevalent during all stages of the pathway from the home, shop or factory, to the landfill.

Officially, the dangers of mercury are acknowledged, but actual practice is extremely variable.

Waste Acceptance Criteria for Class A Land Fills – MfE

Lamps and other mercury-containing wastes are defined as hazardous wastes (NZ Waste List) and the disposal of mercury to landfill is tightly regulated in terms of current Landfill Waste Acceptance Criteria (LWAC).

Spent mercury-containing lamps are considered hazardous when the concentration of mercury exceeds 0.2mg/l (in a prescribed solubility test known as the TCLP). Most lamps (weighing 200-300 g) contain between 0.3 - 20 mg mercury, which means that every 4 - 10 lamps that are land-filled should be carefully monitored.

New Zealand Regulations

Fluorescent lights contain mercury and cadmium. The contents of the tubes should be removed by an approved operator, prior to disposal.’

Here in New Zealand, a number of institutions take this matter seriously and dispose of their mercury wastes correctly, but the majority of used, mercury-containing products in New Zealand are disposed of in an environmentally unsound manner direct into landfill; e.g., mercury switches in motor vehicles are not removed prior to crushing.

Some Councils provide an annual or periodic hazardous waste collection. In many areas, Medichem Ltd services are available for the collection of hazardous wastes, including these mercury products.

If you are uncertain as to what you should be doing, approach your local Council, and ask them how you can recycle your fluorescent tubes, your batteries etc. It is a serious issue, and more attention needs to be given to this environmentally hazardous material.