Final answer:
Toronto's poor air quality is influenced by local industrial activities, transportation emissions, and regional transboundary pollution brought in by wind patterns. High temperatures contribute to the production of ground-level ozone, a major smog component. Natural sources like certain trees also add to organic particles in the atmosphere.
Step-by-step explanation:
The air masses responsible for Toronto's poor air quality include both local and regional factors. Toronto can be affected by smog and pollution due to industrial activities, transportation emissions, and electricity generation, largely powered by fossil fuels. These sources release particulates and gases like nitrogen and sulfur oxides, contributing to the formation of harmful smog. In the summer months, warm temperatures can lead to the atmospheric conditions that enable the formation of ground-level ozone, a key component of smog.
Geographically, Toronto is also situated in a way that sometimes the city can be the recipient of air pollution transported from other areas, including the United States. Wind patterns and weather conditions can bring in polluted air masses, exacerbating local air quality issues. This kind of transboundary pollution highlights the importance of regional cooperation in managing air quality.
Further, natural sources like conifer and citrus trees contribute to organic hydrocarbons in the atmosphere, which are precursors to the organic particle formation in smog. However, these natural contributions are often overshadowed by human-induced pollution sources.