Methodology
Soil samples from burned and unburned areas in Fort McMurray were collected between June 2 and June 19, 2016 by the Regional Municipality of Wood Buffalo (RMWB). In total, 62 soil samples were collected. Additional soil sampling in public areas in burned and unburned public areas will occur after clean-up and debris removal is complete to confirm areas are reclaimed as needed. No additional testing on private property is planned.
Soil was analysed for:
- Petroleum hydrocarbons (PHCs) - Table 9
- Inorganics and general chemistry (including pH) – Table 10
- Metals - Table 11
- Polycyclic aromatic hydrocarbons (PAHs) - Table 12
- Polychlorinated biphenyls (PCBs) - Table 13
- Dioxins and furans – Table 14
Results were compared against established Alberta (ecological and human health) guidelines (Alberta Tier 1).
- Ecological guidelines are protective of the most sensitive receptor. Often, the most sensitive receptor is an aquatic organism or plant. Sometimes, the most sensitive receptor is a human being.
- In the case of community soil samples, humans are not the most sensitive in any of the categories with exceedances. As such, the exceedances of ecological guidelines in these samples do not have an impact on human health.
What we found
A preliminary assessment of the soil data from burned and unburned areas indicates:
- None of the soil samples in any area – burned or unburned – showed an exceedance of human health guidelines (Tier 2).
- Elevated salinity results are an indication of fair to poor soil quality, which may affect plant growth, but not human health.
- There was no indication of metals impact in any community garden soil samples.
- All hydrocarbon concentrations were below human health guidelines. Nine samples from unburned areas and six samples from burned areas had results above ecological guidelines. This could be naturally-occurring, possibly due to presence of organic matter in the soil (e.g., addition of peat). The F3 hydrocarbon fraction does not generally bioaccumulate in plants and, therefore, ingestion of plants growing in these soils is not a health concern.
- Low-level concentrations of Polycyclic Aromatic Hydrocarbons (PAHs) in twelve samples from unburned areas and five samples from burned areas exceeded ecological guidelines, but did not exceed any human health-based guidelines.