Knowledge Center

Many households have air or water filtration systems installed. However, most people are unaware of how to maintain these systems or the importance of doing so. Some salespeople, in an effort to make a sale, exaggerate the functions of filters, painting a rosy picture and touting the products as having numerous features, wide-ranging applications, and requiring no maintenance or upkeep—all to entice customers to buy. Many consumers take these claims at face value, only to end up not only losing money but also facing health risks. Whether it’s an air or water filter, the more advanced or sophisticated the system, the more important regular maintenance becomes. For example, with water filters, the filter cartridges should be replaced at least once a year—or even as frequently as every 3 to 6 months—depending on water quality and usage. Small air filters also require attention; typically, the filter screens should be cleaned and the cartridges replaced every 3 to 6 months. Most central water filtration systems have an automatic cleaning function, and the filter media can remain effective for several years; however, water quality should still be tested and monitored every 2 to 3 years, and maintenance or replacement of the filter media should be performed as needed. Since water softeners do not perform filtration functions, their media typically does not need to be replaced for many years; however, water quality should still be checked regularly, and disinfection and maintenance procedures should be carried out as needed. By Michael Chiu, MWS, CI Previously published in Ming Pao [...]

When people think of air pollution, they tend to associate it with smog, acid rain, or other forms of outdoor air pollution. But have you ever considered the existence of indoor air pollution? The answer is yes—every year, many people experience health problems caused by indoor air pollution. Indoor air pollution can include three broad types of pollutants: particulate matter, chemical pollutants, and biological contaminants. Whether short-term or long-term, exposure to polluted air can lead to a wide range of health problems of varying severity. Many people are particularly sensitive to air pollution, and this is especially true for children and the elderly. In particular, people with pre-existing health conditions—such as asthma sufferers or those with heart or lung problems—may experience worsening of their conditions due to air pollution. Short-term exposure to polluted air can cause adverse physical reactions, including watery eyes (eye irritation), a runny nose, and discomfort in the throat and respiratory system. It may also lead to symptoms such as headaches and dizziness, depending on the pollutant and level of exposure. Furthermore, it can exacerbate conditions in people with asthma and other respiratory diseases. In London, England, during the “Great Smog” of 1952, high concentrations of air pollution were associated with approximately 4,000 deaths during the five-day episode, with estimates of about 12,000 total excess deaths when deaths in the following weeks and months are included. Long-term exposure to polluted air affects physical health, increasing the risk of chronic respiratory conditions, lung cancer, and heart disease; severe or prolonged exposure can [...]

Many people often say that drinking water that’s too pure deprives the body of the minerals, nutrients, and immune-supporting benefits it could otherwise obtain from water, so they advise against drinking such water. What many people don’t realize is that the minerals in water—which come from the air and the ground—are inorganic substances that can nevertheless be absorbed by the human body. The idea that these minerals must first be converted into “organic minerals” before they can be used by the body is not supported by current scientific evidence. Likewise, there is no good evidence that ordinary minerals in drinking water accumulate in our joints, intestinal walls, or arteries and cause arthritis, constipation, or hardening of the arteries, or that they cause kidney and liver stones simply by accumulating in these organs. Plants do require inorganic minerals for growth, and through photosynthesis they convert carbon dioxide and water into organic compounds that can be consumed by animals and humans, but humans can also absorb and use minerals in inorganic forms. Pure water is an effective solvent, but the claim that drinking highly purified water dissolves toxins and inorganic minerals accumulated in the body and causes them to be expelled is not established by scientific evidence. The body naturally regulates and eliminates waste through the kidneys, liver, lungs, and gastrointestinal system, and adequate water intake supports these processes. In particular, drinking enough water helps dilute the urine and can reduce the risk of kidney stones. While purified water can be safe to drink, there is [...]

Status: Archived historical article Last editorial review: October 2026 Water quality experts believe that reports indicating Toronto’s drinking water poses health risks—with 13% of households having tap water that exceeds safety standards—are not alarmist. This is a legacy issue stemming from the fact that some of the city’s underground drinking water pipes are made of the heavy metal lead, which has led to drinking water safety concerns over the years. Certified water quality expert Zhao Wenjie (pictured) points out that the city government is already seeking solutions. Under the current circumstances, the simplest and most effective method is to run the tap for about 5 minutes every morning before drinking the first glass of cold water. To reduce the risks associated with household tap water, residents may consider installing water filters or water softening systems. Daily Lead Ingestion Can Cause Blood Poisoning Zhao Wenjie stated that Toronto’s household tap water has long posed numerous health risks, though these have only recently come to light. From before the 1950s through the early 1990s, the city’s underground drinking water pipes—part of its infrastructure—were primarily made of lead, which was used to transport drinking water to every household’s faucets. The city government used lead pipes because they are rigid, easy to solder, and resistant to damage. However, lead is a toxic heavy metal that, once accumulated in the human body, cannot be excreted. Zhao Wenjie explained that after decades of use, lead pipes naturally flake or leave behind lead residue. As this water flows through household plumbing, [...]

Originally published: May 23, 2014 Status: Archived historical article Last editorial review: October 2026 Source: Canada Metro News [Canada Metro News] Water quality tests on drinking water samples collected from 15,000 Toronto households over the past six years show that as many as 13% of them contain lead levels above the standard. Lead affects brain and nervous system development, with the greatest impact on fetuses, infants, and children under 6 years of age. Doctors warn that symptoms of elevated lead exposure in young children include shortened attention spans, attention-deficit/hyperactivity disorder (ADHD), decreased IQ, and behavioral problems. Compiled report Water quality tests on drinking water samples collected from 15,000 households in Toronto over the past six years show that as many as 13% exceeded lead limits, with some exceeding the limit by more than 2,000 times. Areas with dangerous levels of lead in drinking water are mostly older residential neighborhoods with outdated infrastructure but generally high property values. Those with the highest lead levels include High Park, Lawrence Park (in the area around Yonge Street and Lawrence Avenue), the Annex south of downtown, and residential areas in East York. The samples were collected from faucets by Toronto residents between 2008 and this year and submitted to the city for testing. The Star obtained the results through a Freedom of Information Act request. Health Canada has set the maximum acceptable level at 10 parts per billion, but experts point out that there is no such thing as a “safe” level and that the affected pipes should [...]

AM1540 Sing Tao Chinese Radio Interview – Drinking Water May Contain Various Drug Residues September 22, 2014

AM1430 Canadian Chinese Radio Interview – Excessive Lead Levels in Drinking Water May 20, 2014

Originally published: July 26, 2015 Author: Sing Tao Daily Status: Archived historical article Last editorial review: October 2026 Criticism Over Illegal Disposal of Syringes; Sewage Flows Into Lake Ontario; Drinking Water Contains Drug Components; Experts: Boiling Won’t Eliminate Contaminants [July 26, 2015] [http://news.singtao.ca/toronto/2015-07-26/headline1437890980d5695694.html] Sing Tao Daily Reporter While the lead-contaminated water scandal in Hong Kong’s public housing estates continues to escalate, there are also concerns that drinking water quality in Ontario may be contaminated by medications and illicit drugs. McGill University released a report on water quality in southern Ontario, indicating that drinking water may contain substances such as cocaine and morphine. Senior Certified Water Quality Expert Zhao Wenjie stated that the problem of water sources being contaminated by medications or illicit drugs is not a new phenomenon. This situation arises not only from the indiscriminate disposal of medications or syringes that are flushed into Lake Ontario but also—and primarily—because when people take medication, the human body actually absorbs only 25 to 30 percent of it, while the remaining 60% or more is excreted through the bloodstream and bodily waste, with these contaminants entering Lake Ontario via the sewer system. He explained that Ontario’s wastewater treatment and filtration systems are designed to handle only bacteria in the water; sedimented drug residues cannot be filtered out by wastewater treatment plants, which is why the water quality study yielded these results. Zhao Wenjie also noted that it is not just the toxic substances mentioned in the report, such as morphine and cocaine, but also pharmaceutical contaminants [...]

A CDC review examined drinking-water–associated disease outbreaks reported in the United States during 2013–2014. The report looks at outbreaks linked to pathogens such as Legionella and Cryptosporidium, as well as chemicals and toxins, and discusses how problems within water systems and building infrastructure can contribute to contamination and illness. The report also highlights the challenges of detecting and investigating waterborne disease and notes that reported outbreaks may represent only a portion of the actual burden. For the full report and findings, read the original article below. http://www.cnn.com/2017/11/09/health/cdc-water-contamination-reports/index.html