Dust or airborne particulate matter (PM) varies in size. Dust is produced from blasting, crushing, screening and stacking operations as well as conveyor belts and loader and truck transport on site and trucks offsite. Dust increases corrosion and is harmful to vegetation.
Fine particulate matter can be inhaled and is considered toxic under the Canadian Environmental Protection Act (CEPA). Small respirable particulate matter can be even more dangerous, lodging deep within the lungs and tissue. There is no biological mechanism for clearing it from the body.
Recent studies show that fine particulates pose a greater danger to our health than better known kinds of air pollution, such as smog, Sulfur Dioxide and Carbon Monoxide. There is incontrovertible evidence that increased PM is related to increases in cardiopulmonary disease, asthma, bronchitis, emphysema, pneumococcus and premature death in those with preexisting conditions. The elderly and the young are most affected. Crystalline silica dust is common from processing sand and gravel and is a known carcinogen. Any dust report should include a specific analysis of crystalline silica content and dispersion.
Ontario General Air Pollution Regulation:
This regulation, revoked and replaced on November 30, 2005 by O. Reg. 419/05, prescribes standards for permissible air emissions and the modelling requirements to determine compliance at the POI (point of impingement). A Ministry of Environment and Climate Change (MOECC) Environmental Compliance Approval (ECA) is required in order to discharge into the natural environment. This usually requires a detailed report on all air emissions from a facility including an Emissions Summary Dispersion Modelling (ESDM) report (based on recent methods from the US EPA).
Canada Wide Standards (CWS) for PM were established in 2000. It is important to note however, that that there is no “safe” threshold of PM pollution. The “interim” standards are based on risk assessment “balanced” by the cost of implementation, with the input of “stakeholders”. A recent critical report ”The Air We Breathe”, by David Boyd (David Suzuki Foundation) recommends more stringent legally binding Canadian air quality standards (similar to the US, Australia and Europe).
Summary:
Dust can kill you. Mitigation measures for pits and quarries are often inadequate. Dust studies and instrument monitoring should be mandatory and include detailed analysis of specific mineral content (e.g.: silica, mica etc.). Many experts feel that MOECC allowable PM standards do not go far enough to ensure clean safe air