>Does anyone know if there has been any medical
>research that correlates inadequate kiln ventilation
>with cancer? Marcia Beckett (Lavery)
I believe it is doubtful that it can be shown with research that poor kiln ventilation will cause cancer. This is not because there is a lack of toxins, but there are probably not enough cases of cancer associated with poor kiln ventilation for which there would be no other possible cause for the cancers. Because most cancers have several possible causes, it is difficult to pin point each cause unless it is experienced by many people. When enough cases are found, researchers can do population studies that cancel out other causes
It is possible to take the particular constituents of kiln fumes and see if any of them separately or in combination in heavy concentrations are shown to be carcinogenic (when included in air inhaled by mice). Such laboratory evidence may not stand up in court because it may be too different than the typical human experience. I think one of the kiln vent companies should fund a study of this. If it is done by a university science grad student, depending on the results, it could give them a good boost in sales of kiln vents.
Other air pollution problems are common enough that large population studies can be done more easily. The surgeon general now says that he is confident, based on good science, that secondhand smoke causes 50,000 extra deaths in the US per year. The media reports one study that says diesel fumes cause 20,000 deaths per year in the US. Diesel fumes contain 40 known toxins and some are carcinogens, cause heart problems, and asthma. How many school children are forced to ride on diesel buses each day? In Goshen we had an elementary teacher get very sick because the exhaust from the idling buses was being drawn into the school building ventilation system. I suspect that poorly vented kilns also cause some early deaths, but the number is probably too low for a study to determine a reliable estimate. I was called to troubleshoot in one school near Goshen where I discovered that a snow storm had blocked the roof vent above the kiln. The kiln vent was fumigating half the build
Since cancer is often caused by a combination of oxidants (toxins) that wear down the healthy cell's defenses (causing cells to mutate into self-replicating tumor cells), it is best to avoid all impurities in the air, food, water, and skin contacts. Even too much sunlight is a problem for our skin. On the plus side we can select healthier foods and drinks that supply antioxidants, get enough sleep, avoid being overweight, get some exercise (wedge some clay), and avoid whatever we think is bad.
I hope we all continue to teach with clay. Few materials offer the all the advantages and pleasure of clay with fewer problems. Kiln ventilation problems are often easy to fix with a bit of smart modification. You can see the newest Skutt kiln ventilators on the back cover of recent Ceramics Monthy magazines. To stop using clay would be a real tragedy.