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Environment & Science

Clean Air Sarnia and Area


The Clean Air Sarnia and Area (CASA) community advisory panel is made up of representatives from BASES Environmental Monitoring, provincial and local governments, and First Nations who are dedicated to providing the community with a clear understanding of ambient air quality in the Sarnia area. CASA was formed in September 2015, and works to improve air quality in the Sarnia area by:

  • Sharing information about ambient air quality
  • Identifying and researching local air quality issues
  • Providing recommendations and information to the Ministry of the Environment, Conservation and Parks and BASES Environmental Monitoring
  • Informing the public of local air quality

For more information on CASA’s objectives, responsibilities, and structure, please see our Terms of Reference.

Near Real-Time Air Monitoring Data

CASA provides the public with near real-time data about air quality in the Sarnia area, showing air monitoring readings from seven monitoring stations operated by the MECP, the Aamjiwnaang First Nation, and BASES Environmental Monitoring. Several reports are available to summarize hourly, daily, and monthly data, and statistical reports are also provided to carry out data analysis and better understand the science of air quality.

Ambient air quality monitoring is preferable to modelled emission concentrations because it provides real-world measurements of ambient concentrations and a more accurate assessment of local air quality and cumulative exposures from multiple emissions, including local industrial sources, transboundary polluters, and non-industrial sources. In some cases, air quality monitoring combined with modelled emissions can offer valuable insights, provided the correct modelling tools are used and parameters are appropriately set.

Sarnia Area Environmental Health Project

2008 Study Design 

In 2008, BASES partnered directly with the Ontario Ministry of Environment (MOE) and other stakeholders to design and conduct evidence-based studies of community exposure and health effects. After successfully completing Phase I and Phase II of this work, BASES and the Lambton County Health Study Team recommended a five-year study design. In 2016, BASES members directed funding to the study; however, it was cancelled when other sources of financial support were not realized.    

2018 Study Design 

In 2018, the MECP identified the need for the region to evaluate cumulative emissions, exposure and impacts from multiple air pollution sources. In early 2020, BASES was invited by the MECP to sit as Co-Chair of the study Advisory Committee along with a community volunteer representing the Sarnia-Lambton area. In this role, BASES continues to align with the vision of the 2008 study design team, advocating for: 

  • Use of defensible science-based methods
  • Use of monitoring data to inform air quality standards development and promotion of continuous improvement in Ontario’s air quality
  • Alignment with the Government of Canada’s Air Quality Management System (AQMS)

For more information on the SAEHP, click HERE.

Air Measures and Health Risk 

The Canadian Ambient Air Quality Standards (CAAQS) and the Air Quality Health Index (AQHI) are metrics used in assessing air quality in Sarnia-Lambton. CAAQS are annual air quality standards used to identify persistent air quality issues within a jurisdiction. Exceedances of the CAAQS can lead to management actions, such as emissions reductions. The AQHI is a communication tool used to inform the public about current air quality and what it means to their health. Historical AQHI data from Sarnia-Lambton shows that this region has most commonly been classified as a low-risk location, with minimal action required by individuals to protect their health.