The CBC news featured an article today titled "Diesel pollution vastly underestimated, contributes to global deaths". The article discusses a research study published in Nature that suggests that air pollution from diesel vehicles is more than 50 percent higher than shown in government lab tests. The researchers estimated that the additional pollution equates to an additional 38,000 deaths from soot and smog in 2015.
Over the last two weeks, there have been several news stories related to high concentrations of carbon monoxide in indoor air leading to death. On March 23, 2017, Global News published an article, "16 Mandarin restaurant employees in Scarborough hospitalized with carbon monoxide symptoms". On April 1, 2017, CTV featured an article, "Hotel carbon monoxide leak kills child, sickens others in Michigan", about a carbon monoxide leak at a hotel that killed one child and made approximately twelve other people ill. On April 3, 2017, CBC News published an article, "A life off the grid: Idyllic then deadly" about four people killed from carbon monoxide poisoning in British Columbia as a result of carbon monoxide leaking from a propane-powered hot water tank. On April 2, 2017, the Globe and Mail featured an article, "Most Canadians unprotected against carbon monoxide, fire chiefs say".
Carbon monoxide is an odourless, colourless, tasteless gas that is a byproduct of fuel combustion, irrespective of the type of fuel used. Appliances or motor vehicles that produce carbon monoxide become a risk when there is poor ventilation, and the carbon monoxide accumulates to dangerous levels. At low concentrations of carbon monoxide, adverse health effects may be experienced including tiredness, headaches, muscle weakness or shortness of breath. At high concentrations or when exposed to low concentrations of carbon monoxide over time, symptoms may include dizziness, chest pain or difficulty thinking.
Carbon monoxide combines with the oxygen-carrying sites on hemoglobin in the blood, with an affinity 210 to 240 times higher than that of oxygen. The resulting carboxyhemoglobin is unable to carry oxygen. Occupational health and safety codes recommended a maximum 8-hour exposure limit of 25 ppm.
In order to reduce the risk of exposure to high levels of carbon monoxide in indoor air, the following actions are recommended:
An article in Popular Science by Sara Chodosh and Kendra Pierre-Louis titled "Here's how air pollution kills 3,450,000 people a year" discusses a recently released study on air pollution and premature death. The study, published in Nature, shows that approximately 12% of premature deaths were caused by air pollution released elsewhere in the world. Particulate matter that is 2.5 microns and smaller (PM2.5) is especially problematic because of its ability to transfer from the lungs to the cardiovascular system. The article also indicates that the Clean Power Plan, which President Trump just rescinded, would not only have had significant benefits in terms of greenhouse gas reductions, but it also would have significantly reduced PM2.5, saving lives.
The Globe and Mail featured an article on March 24, 2017 titled "Asbestos found in U of T labs stokes concern from faculty, students". The article indicates that dust containing asbestos has been found in multiple labs at the University of Toronto's medical-sciences building. A major renovation has been undertaken of the building, which is almost 50 years old. Although any asbestos use will be banned in Canada by 2018, the University of Toronto incident illustrates the challenges associated with addressing the legacy of asbestos containing materials.
The March 29, 2017 issue of the Calgary Herald features an article by Shawn Logan titled "Study finds deadly radon gas exceeds safe levels in one of eight Calgary homes". A study by University of Calgary researchers published in CMAJ Open Journal found that 12.4% of the 2382 homes tested in Calgary had radon levels higher than acceptable levels. Radon is the second leading cause of lung cancer in Canada and claims 3200 Canadian lives each year.
The March 2017 issue of the ASHRAE Journal features an article, titled Formaldehyde Emissions from Laminate Flooring by Francis J. Offermann. The article describes an error that the Centers for Disease Control and Prevention (CDC) made in its report on potential exposures to and health risks of formaldehyde in laminate flooring from Lumber Liquidators manufactured in China prior to 2016. The urea-formaldehyde resins used in the medium density fibreboard (MDF) of the laminate flooring in question releases free formaldehyde following installation, but formaldehyde is also released as a result of hydrolysis caused by indoor relative humidity, and this latter source of emissions was not considered in the CDC report. According to the author's own modelling, the calculated cancer risks using the corrected formaldehyde emissions decay rate for laminate flooring is more than 12 times higher than the risks reported by the CDC.
Exposure to Lumber Liquidators laminate flooring represents both cancer and non-cancer health risks. Neither air scrubbers nor ventilation are an effective means of reducing these risks; only removal of the flooring can completely mitigate the risks. The author states that alternate resin systems such as phenol-formaldehyde resin are much more stable than urea-formaldehyde resin, and do not release formaldehyde when exposed to humidity.
This week, the World Health Organization (WHO) released two reports on children's health and the environment. The reports describe threats to children's health such as toxins from improperly recycled electrical and electronic waste. The report also notes that the rise in temperatures and carbon dioxide associated with climate change increases pollen growth, which is associated with increased asthma rates. The report indicates that 44% of asthma symptoms reported in children are related to environmental exposures. The reports can be found here on the WHO website.
New research from Washington University's School of Medicine in St. Louis suggests that welders exposed to airborne manganese at concentrations lower than current occupational health and safety standards exhibit neurological problems similar to Parkinson's disease. The results were published on December 28, 2016 in Neurology ("Dose-dependent progression of parkinsonism in manganese-exposed welders") and suggest that current occupational health and safety standards for welding fumes may be inadequate to protect welders.
Why is Radon a Health Issue?
Radon is a colorless and odourless radioactive gas that is a product of the radioactive decomposition of uranium. Radon is a naturally occurring substance, but when it is in an enclosed space, it can accumulate to concentrations that pose a health risk. Exposure to high concentrations of radon has been linked to an increased risk of developing lung cancer, and radon gas exposure is the second leading cause of lung cancer after smoking. A number of studies in recent years have shown that a significant number of Canadians are living in homes with radon levels above the current Canadian guidelines. In 2012, Health Canada released the Cross-Canada Survey of Radon Concentrations in Homes final report indicating that 6.9% of Canadians are living in homes with radon levels above the guidelines. Early results from a 2016 Calgary study being undertaken by researchers is suggesting that as many as one and five homes are over the maximum acceptable limit.
Health Canada recommends that remedial measures be undertaken wherever the average radon concentration exceeds 200 Bq/m3 in the normal occupancy area. The World Health Organization (WHO) recommends a lower annual average concentration of 100 Bq/m3 as a threshold.
Measuring Radon Levels
Radon tends to be heavier than air and given that most of the radon in homes is from the soil upon which the building stands, Health Canada has recommended that radon testing be done below the third floor. The concentrations of radon in the indoor environment can vary significantly over time. For this reason, long-term measurements typically of 3-12 months are recommended. Testing for radon for less than three months is not recommended. Long-term radon measurements can be done with an alpha track detector, an electret ion chamber, or a digital detector.
In an alpha track detector, the alpha particles from radon and its decay products strike a special plastic or film, creating damage tracks and at the end of the testing period, the film is analyzed by a laboratory. In an electret ion chamber, there is an electrostatically charged disk detector, which experiences a reduction in charge as a result of the ionization from the decay of radon. The electret can be read in the home using a special device or sent to a laboratory for analysis. A digital detector uses an ion chamber, and after an initial measurement period, the device will display the average radon concentration continuously.
Reducing Radon Concentrations
Radon levels in a building can be reduced by:
Mould is a commonly found problem in homes and buildings and it affects people differently. For some individuals, it can lead to allergic reactions including rashes, coughing, eye irritation, or respiratory conditions including asthma in children. In extreme cases, exposure to certain types of toxigenic moulds such as Stachybotrys chartarum has been linked to more serious chronic health issues (though this is an area where research is ongoing). While exposure to mould spores is unavoidable, factors in the home can lead to greater concentrations of allergenic and toxigenic mould. In some cases, mould issues indoors have become so severe that residents are forced to leave their homes until the problem is addressed. Early detection and remediation is critical to avoid more serious and costly problems down the line.
Factors that Lead to Mould Growth
Mould requires moisture to grow. Mould colonies tend to form when mould spores in the air land in areas of high moisture such as:
What to do When You Suspect Mould
Mould is sometimes detectible by sight or smell (a damp odour), but it is often hidden and its presence unknown without indoor air quality testing. Unfortunately, there is no way to tell how bad a mould problem is for two reasons. First, testing is required to determine the type(s) of mould present. Second, often the mould problem goes beyond the surface and exists behind walls or under flooring. If you see or suspect abnormal mould contamination, you should contact professionals to assess and remediate.
It is important for you or your professional to determine the underlying reason for the mould growth. Without first indentifying and fixing the moisture source supporting the mould growth (e.g., condensation or basement leak), your problem will likely continue to persist. Remediation and clean up strategies for mould vary depending on the type of mould and the degree of contamination. In cases of small surface mould, mould can be removed with scrubbing and disinfection with a simple 50% vinegar solution. Commercial cleaners are also available, though not always necessary.
For larger problems, professional advice is typically warranted as the size of the cleanup effort will vary depending on the extent of contamination. When undertaking mould remediation, it is important to have the right personal protection including N95 masks (or better), non-porous gloves, protective goggles and a protective suit.
Preventing Mould Growth and Proliferation
Some effective strategies to prevent mould issues in the home include: