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By the 1970s, research and development involving nanoscale science and advanced miniaturization had begun to emerge, although the widespread development of modern nanotechnology took place later. Nanoscale technologies have since found applications in areas such as military systems, space technology, and security. Miniaturization is an ongoing trend in technological development, and nanotechnology contributes to some of these advances. In everyday life, take cell phones as an example: they once served mainly as a means of making calls, but now they are smaller, more powerful, and equipped with more functions. Camera sensors and electronic components in digital cameras have also become increasingly compact, although miniaturization alone does not necessarily involve nanotechnology. Dual-core 64-bit CPUs in computers are manufactured using advanced semiconductor fabrication processes that incorporate nanoscale features. Nanotechnology has the potential to transform many aspects of human life in the 21st century, and its applications are increasingly integrated into everyday products. Currently, advertisements of all kinds are heavily promoting “nano” products. Consumers should not readily believe every claim made by manufacturers; nanotechnology did not emerge overnight, and the use of the term “nano” does not automatically mean a product is more effective or safer. International standards bodies, including the International Organization for Standardization (ISO), have developed standards covering nanotechnology terminology, measurement methods, and safety practices. These standards can help consumers and industry assess products and claims more reliably. In water and air filtration technologies, particle size is one factor used to assess filtration performance. Particles smaller than 0.1 micrometers are smaller than 100 nanometers (1 [...]

Chlorine has become an indispensable disinfectant in water supply systems worldwide. To prevent harmful bacteria and microorganisms from being present in water sources or distribution pipes, most countries use chlorine or other approved disinfectants to treat municipal drinking water and inactivate these pathogens. However, scientific studies have suggested that long-term exposure to certain chlorination byproducts, particularly trihalomethanes (THMs), may be associated with an increased risk of certain health conditions, including bladder cancer. Evidence regarding other cancers and health conditions, such as liver cancer, stomach cancer, colon cancer, anemia, hypertension, heart disease, and arteriosclerosis, is limited or inconclusive, and these effects should not be attributed directly to chlorine in drinking water. Studies have also shown that during showering, the body can absorb certain volatile chlorination byproducts, such as trichloromethane (chloroform), through the skin and respiratory system. Some exposure assessments have estimated that a ten-minute shower may result in chloroform exposure comparable to drinking several litres of water from the same supply, depending on the water's chemical concentrations and individual exposure conditions. However, this is an estimate of equivalent exposure, not a measurement showing that the body absorbs the same amount as eight glasses of water. Chlorine and chlorination byproducts may also contribute to skin irritation under certain conditions, although claims that chlorine strips proteins from the skin and hair are not well established. The addition of chlorine as a disinfectant to municipal drinking water is essential for preventing waterborne diseases caused by bacteria and other microorganisms. However, if drinking water contains elevated levels of chlorination [...]

Escherichia coli (E. coli) I’m sure many of you have recently seen reports in newspapers or on TV about certain pre-packaged, ready-to-eat vegetables being contaminated with E. coli. Public health authorities may warn the public not to purchase or consume affected products. In fact, there have been numerous warnings—both major and minor—regarding E. coli contamination in drinking water and food over the past 30 years. However, the total of more than 100,000 reported cases cannot be verified without a specific geographical area, time period, and source. Among these incidents, the outbreak that occurred in May 2000 in Walkerton, Ontario—a town with a population of approximately 5,000—where E. coli and Campylobacter contaminated the water supply, resulting in seven deaths and thousands of people becoming ill, garnered significant attention. E. coli is a bacterium commonly found in the intestines of humans and other warm-blooded animals. Most strains are harmless, but certain strains can cause serious illness. The bacteria can spread through animal or human feces and contaminate food and water. Unlike some parasites, E. coli does not form spores or produce oocysts. Properly operated chlorine and ultraviolet (UV) disinfection systems can effectively inactivate E. coli in drinking water. Once humans consume food or water contaminated with disease-causing E. coli, even a small number of bacteria may cause infection, depending on the strain and the individual’s susceptibility. These bacteria can multiply in the body and, in some cases, produce toxins that cause illness. Typically, patients develop symptoms such as diarrhea, nausea, vomiting, severe abdominal cramps, and sometimes [...]

Residents of apartment buildings may face various levels of air pollution issues, such as those caused by interior building materials, furnishings, household products, and furniture that contain chemicals, paint, or preservatives. Since most high-rise buildings or apartment complexes feature shared hallways and ventilation systems, any deficiencies or errors in maintenance or design can contribute to air pollution problems—and in severe cases, may facilitate the spread of airborne pathogens or cross-infection with viruses. To address these air pollution issues, the most important steps are to eliminate and control the sources of pollution, improve air circulation, and install appropriate air purifiers. Residents can help eliminate and control sources of pollution by, for example, cleaning and removing household products containing chemicals, and addressing excess moisture or standing water in indoor potted plants that may contribute to mold growth. They should also move furniture or other items blocking ventilation openings out of the way, or occasionally open doors and windows to improve indoor air circulation when outdoor air quality permits. If residents have implemented the above measures but still find that air pollution problems persist, they should seek solutions and remedies from the relevant property owner or management company. By Michael Chiu, MWS, CI Previously published in Ming Pao Daily News – Updated and Revised in 2026

When people discuss installing water filtration systems in their homes, they often have many questions about them. For example, can these systems filter out most impurities? During the water-softening process, is the sodium chloride (table salt) used by the water softener harmful to the human body? Central water softeners use a physical cation-exchange process to replace calcium and magnesium ions that cause water hardness with sodium ions. Many consumers question the potential negative health effects of drinking this sodium-enriched softened water. Sodium is an essential nutrient and plays important roles in maintaining fluid balance, nerve function, and muscle function. However, excessive sodium intake can contribute to high blood pressure and cardiovascular problems. Data indicates that many adults in North America consume more sodium than recommended. People with certain medical conditions or who have been advised by their doctors to limit sodium intake should take the additional sodium from softened water into consideration when managing their diet. According to the Water Quality Association, there is no evidence that drinking properly softened water causes cardiovascular or other health problems in healthy individuals. Based on the hardness of water in the Greater Toronto Area, a typical central water softener may add a measurable amount of sodium to the water. For example, if softened water contains 80 milligrams of sodium per liter, a person drinking 8 glasses of water (approximately 2 liters) per day would receive about 160 milligrams of additional sodium from the softened water. For most healthy adults, this is a relatively small contribution to total [...]

Point-of-Use (P.O.U.) Water Filters Countertop water purifiers and point-of-use (P.O.U.) systems include technologies such as activated carbon filtration, reverse osmosis, and distillation. To improve the quality of drinking water at the point where it is consumed, P.O.U. systems can be an effective option when selected according to the specific contaminants present. These filters can remove or reduce certain contaminants that may be present in household water or introduced through plumbing, such as lead, chlorine, and certain chemicals and other impurities. Using a point-of-use (P.O.U.) water filter can help reduce many contaminants before the water is consumed or used for drinking and cooking. However, the effectiveness of a filter depends on its technology, design, maintenance, and certification for the specific contaminants being targeted. Central Water Filtration Systems (P.O.E. – Point-of-Entry) Whole-house water filtration systems are installed where the main water supply enters the home, allowing treated water to be distributed throughout the house. Examples include water softeners, activated carbon filters, and combination or hybrid systems. A central (P.O.E.) system can reduce or remove certain impurities and contaminants throughout the home. Depending on the system, this can include hardness minerals, chlorine, sediment, and certain chemicals, providing benefits for plumbing and appliance maintenance, as well as water quality throughout the home. Using a central water filtration system can also reduce chlorine and certain volatile chemicals in the water. When these substances are present at significant levels, reducing them at the point of entry may decrease their release into indoor air during activities such as showering. However, the [...]

Stressful lifestyles, air pollution, and water contamination have contributed to a variety of health and environmental concerns. Recently, some water filter suppliers in Hong Kong have launched products marketed as “energy water” or “health water,” claiming they can help the body absorb minerals, boost immunity, treat chronic illnesses, neutralize excessive acidity in the body, and so on. However, such claims require scientific evidence, and products should not be promoted as treatments for disease without reliable evidence to support their effectiveness. The human body obtains most essential minerals and nutrients from food, although drinking water can also provide certain minerals, including calcium and magnesium. Having an unusually high mineral content in drinking water does not generally cause dehydration, although water with extremely high concentrations of dissolved substances may be unsuitable for drinking and can have other health effects. The pH level of drinking water, provided it is safe and uncontaminated, does not normally have a meaningful effect on blood pH or immune function. The human body has sophisticated mechanisms that tightly regulate the pH of its internal fluids and maintain the balance necessary for normal physiological function. The body needs adequate hydration to support normal circulation, kidney function, digestion, temperature regulation, and many other physiological processes. Water also helps the kidneys eliminate metabolic waste through urine. Therefore, drinking safe, high-quality water and maintaining adequate hydration are important for overall health, although drinking water alone cannot prevent or cure disease. By Michael Chiu, MWS, CI Previously published in Ming Pao Daily News – Updated and Revised [...]

Due to the filtration and adsorption properties of activated carbon, many water filters today use it as an important filtration material. Activated carbon is commonly made from materials such as coconut shells, wood, or coal. Through processes such as heating and activation, a highly porous structure is created, greatly increasing its surface area. The total internal surface area of activated carbon can be extremely large relative to its physical size, which allows it to adsorb a wide range of contaminants. Activated carbon can adsorb many organic compounds and reduce odors and unpleasant tastes caused by certain contaminants. When specially designed and treated, it can also reduce certain chemicals and contaminants, including some pesticides, solvents, and chlorine byproducts. Its effectiveness depends on the type of carbon, the design of the filter, the contaminant, and the amount of water treated. To ensure activated carbon performs effectively, the filter media must be replaced regularly according to the manufacturer's recommendations. Once the media becomes saturated, its ability to remove contaminants can decrease. Activated carbon filters can also remove some suspended particles, depending on the filter's design and pore size. However, ordinary activated carbon should not be assumed to remove very small microorganisms such as E. coli or other bacteria unless the filter has been specifically designed and certified for that purpose. Filtration of particles and microorganisms depends on the overall filter design and is not determined by activated carbon alone. Activated carbon does not effectively remove many dissolved inorganic contaminants, such as calcium, magnesium, fluoride, nitrate, and most [...]

Except for a small number of homes that have their own private wells, most of us get our drinking water from the public water supply system. In general, tap water is regulated by government authorities and is required to meet drinking water standards. However, water that flows over land and through rivers and lakes can dissolve limestone, calcium and magnesium salts, and other naturally occurring minerals. Depending on its mineral content, this can make water hard or soft. With today’s advanced technology comes a vast amount of industrial waste and environmental pollution. Whether hard or soft, water can contain naturally occurring minerals and, depending on its source, various chemical contaminants. Boiling water kills most bacteria, viruses, and other microorganisms, but it does not remove most dissolved minerals or many chemical contaminants. If boiled water is stored improperly, it can also become contaminated again. Therefore, water quality depends not only on whether it is boiled, but also on its source, treatment, and storage. Some contaminants in drinking water can pose health risks when present at sufficiently high concentrations or when exposure occurs over a long period. Depending on the contaminant, long-term exposure can affect organs and contribute to certain chronic health problems. This is why drinking water standards are established to limit potentially harmful substances and why water quality is monitored and tested. Water is essential for the body and plays an important role in transporting nutrients and removing metabolic waste through processes such as urination and sweating. However, water itself is not a universal [...]

Some advertisements and multi-level marketing companies claim that certain calcium supplements or alkaline water can neutralize the acidity in the body’s blood and bodily fluids, thereby treating chronic illnesses and other conditions. Anyone with even a basic understanding of nutrition knows that no food or beverage—including water—can meaningfully alter the pH of blood or gastric juices. Except for urine, which can be affected by acidic or alkaline foods, most parts of the human body maintain a tightly regulated pH level that food and beverages cannot significantly alter. The stomach is naturally acidic, and eating food does not fundamentally change its acidity. Citrus fruits, vinegar, or vitamins such as ascorbic acid will not meaningfully alter the acidity of your blood or stomach. Any food or beverage that passes through the stomach is exposed to stomach acid; it is then neutralized by secretions from the pancreas and other digestive organs before entering the small intestine. Therefore, regardless of what you eat, food becomes acidic in the stomach and is subsequently neutralized as digestion continues. The range of pH fluctuations that the blood and human organs can tolerate is very narrow and must be carefully regulated. Significant changes in blood pH can cause serious physical symptoms and, if severe enough, can be life-threatening. Many marketing companies or individuals, in order to promote their products, emphasize that cancer cells cannot thrive or survive in a highly alkaline environment. While some cancer cells may respond differently to changes in their surrounding environment, the same basic principle applies to normal [...]