4514 Gregg Road
Madison, WI 53705
July 6, 2011
To Whom it May Concern:
RE: Mercury emissions from Crematoria
I am writing in response to some issues raised about a proposed crematorium in Spring Hill.
As background, I am a retired Professional Engineer from Madison, Wisconsin, and specialized in solid waste issues, with mercury from products one of topics on which I have done extensive work. Projects include a mercury flow model for the state of Wisconsin and the US EPA, testimony to a committee of Congress on mercury emissions from crematoria, and a more than 10 year project of a “Summary of References on Mercury Emissions from Crematoria”, with the latest edition having over 140 references.
Mercury emissions come from many sources, with man-made sources being a significant – and controllable – part of the overall picture. While many man-made sources of mercury emissions are in decline due to bans on the use of mercury or control technologies, a rapidly increasing source is from cremation. This may at first seem counter-intuitive, since the use of mercury in dentistry is decreasing. But, the quantity released during cremation is increasing due to two main factors – the number of cremations is increasing, and the number of mercury restorations per person cremated increasing due to improved dental health, which results in more teeth – and restorations – being present in the deceased. As an example, in my own family (which has long handled its deceased through cremation), neither of my parents had any of their natural teeth when they passed away (and thus, no restorations of any type), while both of my two deceased brothers had all of their teeth, with a considerable number of restorations. The American Dental Association noted in a review of my work that amalgam restorations can last an average of 20 years and, anecdotally, I know from personal experience that they can last much longer.
In testimony before Congress last year, the Mercury Policy Project estimated that mercury emissions from crematoria will be about 7,700 kilograms (17,000 pounds) in 2020. This estimate is based on a cremation rate increasing to about 50%, making an interpolation of estimates from the Cremation Association of North America, and estimates of tooth retention and amalgam per cremation as noted by studies in the UK. This estimate compares to an earlier data of the mercury flow model from the US EPA of 2005-2010 emissions of about 3,000 kg (6,500 pounds), and more than a 350% increase from the 1990 level from that same EPA model. This is stark contrast to other sources of mercury from products, many of which (thermostats, thermometers, auto light switches, etc.) which will have nearly zero emissions by 2020, since not only has their use been halted, but their lifetimes are limited.
Unfortunately, while other countries have implemented standards and technology for reduce mercury emissions from crematoria, this has not yet taken place in the US.
It is my understanding that the proposed system near Spring Hill would also not have control equipment which would capture mercury emissions. Instead, the system would have two combustion chambers. While the second combustion chamber can reduce the emissions of combustible material, mercury is not combustible and the quantity released to the environment would not be effected. Mercury is neither created nor destroyed by combustion. While it may change form – such as between dimethyl mercury, methyl mercury, metallic mercury or a compound of mercury – the total quantity will remain the same. In addition, studies have shown that mercury released to the environment is changed between its various forms in nature.
I would be glad to respond to questions that anyone may have on mercury emissions from crematoria, and to both share my work, and if desired, discuss issues by phone, either with individuals or groups.