Air quality

Overview

As a socially and environmentally responsible company, we are very conscious that our mining processes can cause pollutants to enter the atmosphere.  We also understand that some of these emissions may be harmful to people, animals and plant life, and not only in the areas in which operate. 

So we have programmes in place to help mitigate these effects and also to meet our legal requirements in this area.

How we improve air quality

Our main challenges come from greenhouse gases mainly in the form of carbon dioxide produced from the burning of fossil fuels, the clearing of land and some industrial processes. But we also emit dust  from stockpiling or moving material, oxides of sulphur and fluoride  from smelters.

Oxides of nitrogen (NOx) are also emitted,  largely from the combustion of fuels.  These form toxic chemicals - such as nitrate particles, acid aerosols and NO2 - which can cause respiratory problems and contribute to the formation of acid rain and nutrient overloads. 

Work was undertaken in 2005 to determine whether our NOx emissions were significant, based on potential community health or environmental impacts.  We concluded that our NOx emissions do not significantly impact airshed quality because either:

• NOx emissions from our operations are not significant as a proportion of total NOx emissions in an airshed (when other contributors are included), or
• Where our operations were considered to be a significant contributor, airshed quality did not appear to be significantly impacted by NOx emissions (indicated by NOx levels being within regulatory limits).

Our aim is to continually work at putting controls in place to minimise any health or environmental impacts from our emissions into the air. We monitor health in the workplace and have also developed Group-wide occupational health standards that cover such topics as workplace monitoring of particulate gas and vapour exposure.

Our results

We carry out extensive and comprehensive public reporting to a number of bodies including:

• The Toxic Release Inventory in the US.
• The National Pollutant Inventory  in Australia. 
• The National Pollutant Release Inventory in Canada.
  

Our 2006 results show that levels of oxides of sulphur (SOx) emitted into the air have decreased by 12 per cent since 2005. Emissions of fluorides have, however, increased by 10 per cent.  Roughly 20 per cent of this increase was due to improved measurement techniques at Rio Tinto Aluminium Bell Bay (rather than increased emissions).

A total of 87 dust related complaints were received by operations last year, representing a 21 per cent increase since 2005.

To see fuller explanations about these results, please go to SOx, Fluorides and Dust.