The Environmental Cost and Damage Cremations Incur


Cremation has become a more popular alternative to burial. However, cremation is not without an impact on the environment and as a result ‘Green Burials’ are now looked into as a further alternative.

Crematorium furnaces combust at very high temperatures, 1590-1797 degrees Fahrenheit or 870 – 980 degrees Celsius, and it takes at least an hour to incinerate the body. The burners can range in power from 150 kW to 800 kW. Most furnaces are run by natural gas. The air supply is controlled. A 68 kg body which contains 65% water will require 100 MJ of thermal energy before any combustion will take place. This is equivalent to 3 cubic metres of natural gas or 3 litres of fuel oil. Additional energy is necessary to preheat the furnace. The furnace is lined with refractory ceramic bricks and to produce them requires lots of energy and materials.

Calcified compounds within cremains can contain metals such as lead, boron, cadmium, chromium, cobalt, copper, tin, lithium, magnesium, manganese, nicket and strontium. Metals such as aresenic and selenium, though present in a live human body, are volatile and decompose quickly upon burning. Levels of toxic metals in cremains are not regulated although all non-combustible materials must be removed from the corpse. Pacemakers must be removed as they explode and will damage the furnace. Dental metal fragments must be removed. The body is burned within the coffin or a cardboard box. Any bone fragments left after they cool are ground in a separate process and added to the ash. Fumes produced are computer controlled. The flue gases are vented to the atmosphere through a refractory-lined flue. The gases are at a very high temperature and are cooled. However, gaseous emissions are by far the greatest source of cremation pollution.

In addition to harmless compounds such as water vapor, emissions include carbon dioxide, carbon monoxide, nitrogen oxide, sulphur dioxide, hydrogen chloride gas, hydrogen fluoride, mercury vapour . Organic compounds such as benzenes, furans, acetone are also emitted and these react with the hydrogen chloride and hydrogen fluoride under combustion conditions to form polychlorinated dibenzodioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) both of which are carcinogens. A study by the Cremation Association of North America has found that filtering crematorium fumes has little effect on the toxins released. However, when compared to yearly toxin release world wide, crematoriums contribute only a very small fraction of harmful compounds or greenhouse gases.