A bio-mat is a layer of slimy dark-grey colored bacteria that forms and lives in your absorption field. This bacteria can slow your systems ability to absorb water by physically clogging the soil interface. Some bio-mat is normal and in fact healthy. When nutrient ladened wastewater passes through the bio-mat, it consumes some of the wastewaterâs nutrients, partially cleaning the water before it passes into the soil.
EPA assesses the cancer risk associated with exposure to the pesticide in food over the course of a person's lifetime. EPA then determines whether that cancer risk can be considered negligible. In general, EPA will grant a tolerance and register any pesticide that poses a negligible or no-cancer risk. The notion of negligible risk is an attempt to set a standard below which the cancer risk is so small that there is no cause for worry from a regulatory or public health perspective. EPA's pesticide program defines a negligible risk a one-in-a-million or less chance of getting cancer as a direct result of a lifetime of exposure to a particular substance.
Other pesticides are less toxic, but too much exposure to them also will cause harmful effects. A good equation to remember is: Hazard = Toxicity x Exposure Hazard is the risk of harmful effects from pesticides. Hazard depends on both the toxicity of the pesticide and your exposure. Exposure When a pesticide contacts a surface or organism, that contact is called a pesticide exposure. For humans, a pesticide exposure means getting pesticides in or on the body. The toxic effect of a pesticide exposure depends on how much pesticide is involved and how long it remains there.