What is NOA? The acronym stands for naturally occurring asbestos and it is the name given to the silicate minerals serpentine and amphibole; sheet silicates that in certain environmental conditions, form thin crystals in parallel alignment – with the appearance of cotton or silk. The term NOA can also be used to describe different minerals that crystallise in a fibrous manner resembling asbestos, and minerals that can produce elongated particles when broken or crushed.
What happens when the polluter is the environment? Recently, we have started to view the environment as a source of substances likely to be harmful to human health. Such as asbestos, which occurs naturally in rock.
The most significant risk from NOA is that anyone exposed can later expect to form an asbestos-related disease such as asbestosis – the chronic inflammation of the inside of the lungs (which is a result of exposure to high concentrations of asbestos), lung cancer and mesothelioma – a cancer that occurs in the protective lining that covers most of the body’s internal organs. These latter two diseases result from exposure to lower concentrations and are the largest concern for NOA.
Not all particles that might find themselves classified as NOA have the same disease risk, and trying to determine the exact risk from low-level environmental exposures is not easy. For the asbestos particles to become airborne, the rock or soil needs to be disturbed.
The nature of the soil and local climate, as well as the type of activity causing disturbance are significant. Simple erosion isn’t as much of a risk as man’s activities – such as mining and quarrying, excavation for construction, farming, landscaping and gardening. People carrying out these activities have the highest risk occupations, but second-hand exposure is also possible for local residents. Other soil disturbers are recreational activities that move soil such as riding motorized vehicles, bicycles, jogging and other sports. So the people who can’t keep up in a group would be the ones exposed to greater quantities than the leaders.
Once it is known that a region has NOA, the local population must determine whether the risk is tolerable, and this becomes more difficult with increasing uncertainty in the assessment. In each situation, NOA carries a unique combination of risk assessment and social issues, such as employment, income and property values. Failure to come up with an acceptable solution to the issue of NOA leads to litigation and political and social recriminations, reduction of property value, and ultimately the possibility of impaired future health.
NOA is an issue of study, debate and concern within the affected areas of the US today, and also for some countries around the Mediterranean, such as Italy and Turkey, where NOA is relatively common. However, the widespread occurrence of these minerals suggests that this matter will become an issue for many other countries in the future.
