Consequences of Large-scale Production of Marijuana in Residential Buildings

Abstract

Based on the data from the breadth of Canada (∼4300 km), one-third of Canadian homes have ventilation rates below the recommended standard of 0.3 air changes per hour and are at risk for moisture problems. For the purposes of this investigation, a literature review was performed on the health risks associated with exposure to living and drying marijuana plants and the fungi associated with large numbers of indoor plantings. Analysis was made of the impact on Canadian homes if used to grow marijuana. These are commonly called “marijuana grow operations” based on measured ventilation rates from homes in Windsor, Ontario and Regina, Saskatchewan (representing diverse climates) and derived moisture loadings from published data. The growing and drying of marijuana plants contributes considerable amounts of water vapour to the indoor environment. Depending on the scale of production, considerable mould damage in the building can result. There are also a number of abiotic hazards resulting from marijuana production including pesticides, carbon monoxide, and products of unvented combustion appliances. Both indirect and direct evidence are described for the health impact of living in these conditions. This has a number of implications in terms of documentation and personal protection for industrial hygienists, home inspectors, and public health officials.