Environmental Hazards

Asbestos

From Wikipedia,
At the turn of the last century, asbestos was considered an ideal material for use in the construction industry. It was known to be an excellent fire retardant, to have high electrical resistivity, and was inexpensive and easy to use.

The problem with asbestos arises when the fibers become airborne and are inhaled. Because of the size of the fibers, the lungs cannot expel them. They are also sharp and penetrate tissues.

Health problems attributed to asbestos include

** Asbestosis - A lung disease first found in naval shipyard workers, asbestosis is a scarring of the lung tissue from an acid produced by the body's attempt to dissolve the fibers. The scarring may eventually become so severe that the lungs can no longer function. The latency period ( meaning the time it takes for the disease to develop) is often 10-20 years.
** Mesothelioma - A cancer of the mesothelial lining of the lungs and the chest cavity, the peritoneum (abdominal cavity) or the pericardium (a sac surrounding the heart). Unlike lung cancer, mesothelioma has no association with smoking. The only established causal factor is exposure to asbestos or similar fibers. The latency period for mesothelioma may be 20-50 years. The prognosis for mesothelioma is grim, with most patients dying within 12 months of diagnosis.
** Cancer - Cancer of the lung, gastrointestinal tract, kidney and larynx have been linked to asbestos. The latency period for cancer is often 15-30 years.


Carbon Monoxide

From Wikipedia,
Carbon monoxide, with the chemical formula CO, is a colorless, odorless, and tasteless gas. It is the product of the incomplete combustion of carbon-containing compounds, notably in internal-combustion engines. It has significant fuel value, burning in air with a characteristic blue flame, producing carbon dioxide. Despite its serious toxicity, CO plays a highly useful role in modern technology, being a precursor to a myriad of products. It consists of one carbon atom covalently bonded to one oxygen atom. It is a gas at room temperature.

Carbon monoxide, though thought of as a pollutant today, has always been present in the atmosphere, chiefly as a product of volcanic activity. It occurs dissolved in molten volcanic rock at high pressures in the earth's mantle. Carbon monoxide contents of volcanic gases vary from less than 0.01% to as much as 2% depending on the volcano. It also occurs naturally in bushfires. Because natural sources of carbon monoxide are so variable from year to year, it is extremely difficult to accurately measure natural emissions of the gas.

Carbon monoxide has an indirect radiative forcing effect by elevating concentrations of methane and tropospheric ozone through chemical reactions with other atmospheric constituents (e.g., the hydroxyl radical, OH.) that would otherwise destroy them. Carbon monoxide is created when carbon-containing fuels are burned incompletely. Through natural processes in the atmosphere, it is eventually oxidized to carbon dioxide. Carbon monoxide concentrations are both short-lived in the atmosphere and spatially variable.

Anthropogenic CO from automobile and industrial emissions may contribute to the greenhouse effect and global warming. In urban areas carbon monoxide, along with aldehydes, reacts photochemically to produce peroxy radicals. Peroxy radicals react with nitrogen oxide to increase the ratio of NO2 to NO, which reduces the quantity of NO that is available to react with ozone. Carbon monoxide is also a constituent of tobacco smoke.