Mould contamination in homes used as marijuana growhouses

Source: Marie-Alix Halewyn¹

In the last several years, the culture of cannabis, also known as marijuana, has seriously expanded across Canada. Because the climate in Québec is cold, offenders tend to favour indoor growing. More productive and more discreet, indoor installations allow residential growers to harvest three or four crops a year, versus just one outdoors.

Thus between 1981 and 2004, the number of marijuana growing offences has increased by 460%. In 2004, the types of operations were broken down as follows: 47% inside of dwellings, 34% in wooded areas and 19% on agricultural land. Based on statistics compiled by the various Québec police forces, since 2000 there have been several thousands of marijuana growhouses in Québec (see diagram on the next page). A high proportion of these houses are found in the area comprised of Montréal, Laval, Lanaudière and the Laurentians.

Moreover, different police forces in Québec seized almost 30,000 seedlings and cuttings in 2007-2008, in addition to 781,652 seized as part of the Cisaille et Boutures programs².

A lucrative crop

A mature cannabis plant is worth between $1,000 and $1,500 on the resale market, making this a very lucrative crop. In eight years, the percentage of the psychoactive substance contained in the cannabis produced in Québec, called tetrahydrocannabinol (THC), has gone from 5.5% to 11.5%, making Québec pot a very desirable product. In addition, it is relatively easy to grow between 200 and 900 plants (300 to 500 on average) in a well-equipped basement over a period of only four months.

Conditions conducive to fungus contamination

Cannabis can be grown indoors using a series of containers of potting soil irrigated by automatic systems. It can also be produced using more sophisticated hydroponic or areoponic systems. In a closed hydroponic system the roots are in permanent contact with a complete nutrient solution, whereas in an aeroponic system, they are in contact with air and a mist of nutrient solution sprayed by diffusers. The presence of these systems indoors creates relative humidity rates between 40% and 90% (usually around 85%). In addition, cannabis growing requires powerful lighting (up to sixty 1000-W lamps) and temperatures between 25°C and 28°C. These hot and humid conditions are optimal for marijuana growing, but also for the proliferation of moulds.

Moulds are live organisms that grow naturally outdoors. They can be brought inside by air movements and the comings and goings of humans or animals. In order to develop and multiply, they require the presence of appropriate environmental conditions (humidity and temperature) and nutrients such as those found in building materials (wood and paper cellulose). As we have seen, all these conditions are rife in dwellings used as marijuana growhouses.

Impacts of fungus contamination on a building and the health of its occupants

Apart from the risk of explosion due to solvents used in making marijuana oil, or fires caused by electrical malfunctions, a high rate of humidity maintained over long periods is the main cause of damage to a building. High humidity rates cause building materials to rot and moulds to proliferate. Widespread fungus contamination is associated with potential health problems for the occupants of the dwelling. These can be very severe and go from respiratory tract ailments or asthma exacerbation to even more serious symptoms for those more at risk. People who have risk factors such as a chronic respiratory disease or a weak immune system can develop mycotoxicoses, hypersensitivity pneumonitis, and respiratory or systemic infections.

Decontamination of a mould-infested home is sometimes possible, albeit costly. According to the Insurance Bureau of Canada, effective decontamination of a major fungus infestation costs an average of $40,000. Even at that, in some worst-case scenarios, after two or three crops little can be done to save an infested house, and razing becomes the only solution.

Given this, it is easy to see why offenders will first try to mask the damage. In some cases, damaged walls are repainted or even replaced. This cosmetic work can temporarily hide problems caused by chronic humidity, but is usually not enough to eliminate the mould, as the humidity accumulated in the structures frequently resurfaces in materials, whether they are new or simply fixed up to look good.

Clues that a property has been used as a growhouse

Many types of properties are used for marijuana growing (cottages, apartments, suburban homes, etc.) and they are spread out throughout the province. Inside the dwelling, several clues that a high humidity rate was maintained over a long period of time can tip off the fact that a property has been cosmetically altered for resale purposes. They include the relative humidity rate, clogged holes in the ceiling and cupboard floors, small torn pieces of aluminum foil held by staples, unconnected chimney flues in the roof space (attic), odours (sometimes hidden by perfumes), the visible moulds, bubbling of gypsum board walls, blackened woodwork or round stains on the floor. But the presence of these signs is often not enough to sow doubt in the mind of an inexperienced buyer who visits the property, and so the problems can be difficult to detect before purchasing. These concealed defects can even stay hidden until the new occupants undertake renovation work requiring the opening of walls. This is where the sometimes disastrous extent of the problem is brought to light.

Other revealing clues are sometimes visible from the outside, such as barricaded widows, the presence of several ventilators on the roof, a modified or very recent electrical mast, wiring that goes in directly through a window (without going through the electric meter), or a Hydro-Québec meter with a broken seal. In winter, ice forming outside the chimney and the kitchen and bathroom fans as well as excessive condensation and frost on windows are telling signs of an abnormally high humidity rate. Finally, the presence of condensation and moulds on cold surfaces, such as the north wall, are signs to watch for.

The legal environment

In addition to financial losses (property devaluation, cost of decontamination), growhouses resold in poor condition to unsuspecting buyers can pose serious health risks for the new occupants. But the legal environment can make it difficult to prevent these fraudulent sales.

The legal aspects related to marijuana growing include the notions of offence-related property and proceeds of crime. A growhouse is considered an offence-related property since it was used to commit an illegal act. In addition, the offender’s vehicle and his bank account can also constitute proceeds of crime if these are found to have been acquired with profits resulting from crime, a fact that is often difficult to prove. This nuance becomes important since the growhouse used to commit the crime becomes seizable if the offender is the owner. However, it is not always possible to identify the culprits or even the owners, or indeed to intervene in a timely fashion.

Following a search in a growhouse, the police can lay charges and request a freeze order, legally preventing a person from disposing of the building concerned or from carrying out a transaction involving it. Although the order is always served to the accused, the owner of the immovable, the municipality and the mortgage creditors, the time lapse – even if short – is sometimes enough to allow the offenders to make cosmetic alterations to the house and resell it, sometimes with the help of an ill-intentioned real estate broker. The freeze order is also published by the Bureau de la publicité des droits, but only a week or two after it has been issued, again allowing time for illicit transactions. Currently, the OACIQ and Sûreté du Québec are advising real estate brokers, buyers or public health authorities who want information concerning a house in this regard, to contact directly the criminal division of courthouse of the region concerned.

Creation of a register

The delays involved in publishing cases and the multiple sources of information make potential buyers and the real estate brokers representing them vulnerable to fraudulent transactions. The Organisme d’autoréglementation du courtage immobilier du Québec (OACIQ) deems this situation unacceptable and is demanding that its licence holders have access to a common register that would list all the properties for which a search warrant has been issued. Such a tool would enable a real estate broker or agency to inform potential buyers in real time.

Benefits of partnerships

In addition to the legal difficulties surrounding this issue, many stakeholders are concerned with the health problems associated with the presence of moulds in these homes and would like to develop partnerships in order to find an effective modus operandi to identify unhealthy dwellings and prevent the sale or lease thereof. To date, many activities have helped educate stakeholders about the benefits of such partnerships.

Seminar organized by the Association des courtiers et agents immobiliers du Québec (ACAIQ)

In addition to regularly informing its licence holders, in fall 2005 the ACAIQ (former name of the OACIQ) had held a seminar on the different aspects of the growhouse problem. On this occasion, the Association had invited representatives from Health and Social Services, Public Security and Justice, police forces and building inspectors, financial institutions, insurance companies and real estate brokers. The two main objectives were uniting to better fight this problem and educating the public. The event was a first in Canada. The seminar received major media coverage, thereby helping to inform a vast public about what many have come to consider a veritable plague.

Meeting with the Sûreté du Québec (SQ)

In 1999 the Sûreté du Québec set up a program to fight the expanding production and traffic of marijuana. The main purpose of this program, called Opération Cisaille, is to destabilize the criminal organizations that are overseeing marijuana production and distribution. Although the efforts of this special squad have borne fruit and upwards of 700,000 plants were seized in fields in 2005 and 781,652 plants during 2007-2008 period, police recognize the importance of partnerships, including with public health authorities, in dealing with the increasing number of growhouses and the threat they pose to the health of future occupants. According to the SQ, homes searched during the operation and that were used as growhouses for two to five-year periods were completely contaminated by mould.

Aware of the social issues involved and the harmful effects on health, the Sûreté du Québec has deemed it relevant to alert the Table nationale de concertation en santé environnementale (TNCSE), which includes an environmental health representative from each of the health and social service regions, to the magnitude of this phenomenon in Québec. Because these operations pose a health risk for many people, police are seeking the help of public health authorities in an effort to find a workable solution to limit the resale and lease of contaminated dwellings. Potential solutions are currently being examined.

Conclusion

In the last few years, indoor marijuana growing has considerably expanded in Québec. The environmental conditions created in growhouses (high temperatures and humidity rates, presence of organic matter) are conducive to the proliferation of mould. The extent of fungus contamination observed in these environments is such that it poses a health risk for potential occupants. However, the current legal environment makes it difficult to prevent fraudulent transactions. The solution could involve creating a register of homes for which search warrants were issued, as well as the development of partnerships. In this regard, the collaboration of public health authorities could prove beneficial in resolving the problem.

¹ Source: Marie-Alix Halewyn, Direction des risques biologiques, environnementaux et occupationnels, Institut national de santé publique du Québec, 190, boulevard Crémazie Est, Montréal (Québec) H2P 1E2
Telephone: 514 864-1600, Ext. 3204
Fax: 514 864-7646
² Bilan 2007-2008 des efforts québécois de lutte contre le crime organisé - Direction de la prévention et de la lutte contre la criminalité - Ministère de la Sécurité publique.