November 12, 2023

To: Chair Lehman and District Councillors
District of Municipality of Muskoka
70 Pine Street
Bracebridge, ON P1L 1N3

RE: District Council Meeting, November 20, 2023
Agenda Item on Official Plan of the Township of Muskoka Lakes (TML)


Mr. Chair and District Councillors:

Being unable to delegate to the above meeting, I am herein submitting factual human health information that is highly relevant to the District’s consideration of the TML Official plan provisions for New Mineral Aggregate Operations.



Action proposed by the District to decrease to 500 metres the minimum distance from new mineral aggregate operations to waterfront shoreline areas, would seriously increase the risk posed by fine particulate matter (“dust”) from aggregate operations to human respiratory systems (lungs), particularly those of children.

Factual Considerations

1. The Source of the Problem

  • Aggregate operations release large quantities of fine particulate matter (“dust”) into the air.
  • Many of these particulates are of such a small size that they are difficult to capture, travel for long distances (100’s of kilometres) in the air, and penetrate deeply into the lungs.

2. Human Health Impacts

  • Since about 1955, the evidence for serious human health impacts from fine particulates has grown steadily – each new study indicating that they are more serious than previously understood. Some of the world-leading work in this field was done here in Ontario.
  • Health impacts of fine particulates include premature death, hospitalization, respiratory distress, heart attacks and other impacts that are key contributors to $ billions in health system costs each year in Ontario alone (ref. Ontario Medical Association, 2005).
  • Children are more at risk from fine particulates due to their physiology, status of development and their likelihood of being outdoors and physically active for long hours, especially at a cottage during summer.
  • The increase in childhood asthma is well known. Though the reasons for this are not well understood, air pollution, including particulates, likely plays a role.

3. Mitigation Possibilities

  • Most fine particulate emissions from aggregate operations are in the form of “fugitive” emissions, which means that they cannot reasonably be expected to be collected. Such emissions would normally include those from blasting, crushing, materials processing, loading and trucking. They are thus difficult to treat in the way that emissions from a smokestack can be treated to remove particulates. Fugitive emissions can in some cases be reduced, for example by water sprays on crushers or road surfaces. However, performance limits on such efforts are extremely difficult to monitor and enforce. As a result, substantial fine particulate emissions are virtually inevitable from aggregate operations.
  • The Province may apply point of impingement standards to determine if air quality standards are likely to be met at the quarry operation boundary. These however have a number of significant limitations and drawbacks.
  • From the above considerations, the only practical way to greatly reduce the health impact of fugitive emissions is to locate the source at substantial distance from human populations, and most notably from children.

Relationship to Township of Muskoka Lakes Official Plan

  • In consideration of the nature of fine particulate matter, there is likely no practical safe distance for a quarry operation from humans, notably children. However, a distance of 500 metres is, in my opinion, far too close to be considered as adequately protective of human health, particularly with respect to children. Permitting a new quarry is the occasion when it is possible to locate them as far away as reasonably possible from human habitation. (Existing quarries are not the subject of this letter)
  • Other than provisions for locating a new quarry a minimum distance from waterfront areas, there are no provisions and wording in the Township of Muskoka Lakes Official Plan (nor the District of Muskoka Official Plan) that are adequately protective of human health from the effects of fine particulate matter.
  • The only practical option for protecting human health from quarry dust is clear imperative direction such as, for example, “no facility [meeting this description] shall be located within 2000 metres of waterfront areas”.


In consideration of the human health impacts of fine particulate matter from mineral aggregate operations, particularly on children, I strongly recommend that the District Municipality of Muskoka does not in any way impede the Township of Muskoka Lakes from requiring as large a distance as possible between Waterfront Areas and new mineral aggregate operations. In no case should this distance be less than 2000 metres.


I am aware of rationale that may be put forward alleging that recommendations such as the above are impractical. I do not believe this to be the case and am prepared to discuss this further if requested.


Respectfully submitted,

Geoff Ross



MSc. Human Physiology (1976), University of Toronto, Faculty of Medial Sciences

Retired Professional Engineer, after a career primarily with Environment Canada, dealing with air pollution control, including:

  • represented Environment Canada as an expert witness in provincial environmental assessment hearings;
  • member of Canada-U.S. Air Quality Accord negotiating team;
  • represented Canada on United Nations Task Force;

All of the above dealt with air emissions in the context of their associated health impacts



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