Efficacy and desirability of use of water filters come under scrutiny
Hong Kong may enjoy reputedly one of the safest water supplies in the world, but this does not seem to deter consumers from installing water filters to the taps in the household.
The Consumer Council has tested 7 water filter models with filtration capacities of up to 2,500 litres.
The test sought to assess the performance of the water filters in the removal of contaminants in tap water - at 4 different points of filtration, i.e. 375 L, 750 L, 1,500 L and 3,000 L.
Ten types of contaminant were introduced in tap water for testing purposes: turbidity, E. coli, chlorine, chloride, fluoride, chloroform, pesticide (methamidophos), lead, copper and iron.
On the whole, the results were satisfactory. With some variations, all samples were able to remove the contaminants as claimed. A few could even remove the "non-removable" such as dissolved metals.
Most samples were found to perform better at the earlier stage of the test, especially with the removal of turbidity, E. coli, chlorine, lead, chloroform and methamidophos, but only some could retain this capability throughout the entire test.
One common deficiency most samples shared was in the removal of dissolved iron or copper; most were also weak in the removal of fluoride and chloride.
On the cartridge life of the water filters, the tested models were found to range in average cartridge life from 550 L to over 3,000 L. The cartridge life test was terminated when the flow rate fell to one third of the original rate.
In choosing a water filter, consumers are advised to try to understand the removal capability of different filtering materials that come with the filter, and the contaminants that they wish to remove. Look for the one that targets their specific problem, taking into account also the price and the availability of the replacement cartridge.
The test report, on the other hand, noted the Water Supplies Department (WSD) view that given the quality of Hong Kong's tap water, the use of water filters is not necessary if not undesirable.
According to the WSD, the quality of tap water supply conforms to the Guidelines for Drinking-Water Quality recommended by the World Health Organization, and is monitored by extensive sampling and testing at treatment works, distribution systems and customers' taps.
A trace amount of residual chlorine, a chemical widely used worldwide as disinfectant for drinking water, is maintained in the supply system in order to safeguard the water from possible contamination.
Consumers are emphatically assured that pathogenic bacteria and macroscopic organisms as well as heavy metals and pesticides are removed in the water treatment process.
Hong Kong's tap water is safe without boiling, according to WSD. Only if one has doubt about the cleanliness of the supply system in a building, it is advisable to boil water for drinking.
As such, the WSD does not recommend the installation of water filters because they may become ideal breeding grounds for bacterial growths and give rise to health hazards if they are not properly maintained.
Consumers are reminded on the need of proper maintenance of water storage tanks and water pipes in their buildings, the lack of it may affect the quality of water in the household.
The WSD has revealed that over the past years, it has found advertisements of water filters or other bottled water with messages which discredited the quality of tap water.
These included ads that misrepresent the severity of contamination of the Dongjiang water source affecting the quality of tap water, mislead the public to believe that chlorination of tap water is cancer-causing, exaggerate the amount of contaminants in tap water, and convey the misleading message that tap water should be free of all dissolved minerals.
The WSD has issued warning letters to the concerned suppliers to withdraw such advertisements or amend the misleading information.
Fungi-produced toxin found in some apple juice test samples
An apple a day keeps the doctor away, so goes this time-honoured piece of health advice.
But that is true only if the apple is not contaminated by certain fungi which produce a toxin called patulin.
For patulin has been shown to suppress the immune system and the nervous system of laboratory animals.
To assess the extent of the problem in the Hong Kong market, the Consumer Council and the Food and Environmental Hygiene Department have jointly conducted a test on 30 prepackaged apple juice drinks and 15 freshly squeezed apple juice.
It was only last month that the Codex Alimentarius Commission (CAC) has adopted an international health standard permitting a maximum level of 50 μg/kg of patulin in apple juice and apple juice ingredients in other beverages.
Applying that standard, the results of the joint test showed that the freshly squeezed samples fared comparatively better than those of prepackaged.
In the freshly squeezed group, only 1 out of the 15 test samples was found to contain patulin with its level below the CAC limit.
In the prepackaged group, patulin was detected in 8 of the 30 test samples, with one of them in excess of the CAC limit but subsequent follow-up tests on 2 samples of this brand showed that their patulin level was within the CAC requirement.
So, what is the amount of patulin that one can consume in daily intake? The Joint Food and Agriculture Organization and the World Health Organization's Expert Committee on Food Additives have set a Provisional Maximum Tolerable Daily Intake of 0.4 μg/kg for patulin.
The public is assured that it is, therefore, unlikely that moderate consumption of apple juice will cause great health concern. But they, consumers and suppliers alike, should be mindful of not using rotten or moldy fruit to prepare apple juice drinks.
Apples and apple products should be transported and stored properly to avoid physical damage; the storage temperature of peeled or cut apples and squeezed juices should be kept below 4°C.
Ozone generators not suitable for person use as portable air purifiers
Are portable personal air purifiers which came into prominence during the SARS outbreak, suitable for use in protecting users against the SARS virus or, for that matter, any viruses or bacteria?
The answer is a resounding NO, according to a Consumer Council research on 9 models of this ozone-generating gadget.
Not only that; the ozone that these devices generate, when inhaled, is harmful to health.
Ozone in high concentration, according to the Hong Kong Medical Association, can damage the lungs especially for persons with asthma or other chronic respiratory diseases.
Even relatively low amounts of ozone can cause chest pain, coughing, shortness of breath and throat irritation.
In the test, the samples were examined whether they generate excessive ozone with reference to the IEC (International Electrotechnical Commission) safety standard for household air-cleaning appliances - since there is currently no international public health standard applicable to this type of product.
The IEC standard requires that the maximum ozone concentration measured over a period of 24 hours be less than 0.05 ppm (parts per million). The test was conducted in a room with dimensions 2.5 m x 3.5 m x 3 m maintained at 25oC and 50% relative humidity.
Of the 9 test samples, 3 were found to exceed the maximum limit by 1.5 to 3.5 times, posing health risks to the users.
Samples that generate ozone at low concentration, however, are doubtful in effectiveness for the purpose these products are purportedly designed. According to a study of the U.S. Environmental Protection Agency, available scientific evidence has indicated that at low concentration:
- Ozone has little potential to remove indoor air contaminants.
- Ozone is not effective at removing many odour-causing chemicals.
- Ozone applied to indoor air does not effectively remove viruses, bacteria, mold or other biological pollutants.
The Department of Health advises consumers not to use ozone-emitting personal air purifier, especially during exercise, in view of the health risk associated with the possible exposure to high ozone level.
To improve indoor air quality, the most effective way is to eliminate sources of pollution (e.g. create a non-smoking environment, avoid cooking and using paints, glues, paint-stripper and varnishes in confined spaces).
Also, maintain good ventilation by opening windows, and use cooker hoods and exhaust fans if necessary. Keep your home clean in order to minimize the growth of bacteria, mold or other micro-organisms.
The research findings are only applicable to ozone-emitting portable personal air purifiers, and may not be applicable to air purifiers that generate ozone for air pollution control, with monitoring and/or removal mechanism to reduce the residual ozone in the purified air to a safe level.
Ozone has also been used in the industry, for example, for the purification of water or decontamination of unoccupied space.
Economy takes precedence over nutrition in consumer choice for fast food
The nutritional value of fast food has fared poorly in a survey of the Consumer Council.
This is the single most cited area which fast food operators will need to improve to enhance consumer satisfaction.
Nearly 40% of the 1,047 respondents of local residents aged 15 or above, indicated that they were not entirely happy with the nutritional value of fast food.
Nonetheless, when choosing to patronize fast food restaurants, nutrition is not always on the mind of consumers.
Consistently high in the ranking of attributes which determine consumer patronage of fast food restaurants, is the economy of the meals that these eateries offer.
"Reasonableness of price" topped all other attributes in the stated importance scale (the level of importance stated directly by respondents in the survey), and the satisfaction driver scale (factors determining the overall satisfaction level).
According to the survey conducted in December 2002, consumers on average spent $16.6 to $33.9 per meal per person.
Following closely in the ranking was the taste of the food. But consumers demand more than just cheap, tasty fast food.
Attributes that ranked high in the scale of stated importance covered a broad spectrum of consumer expectations: (1) reasonableness of price, (2) taste of food, (3) hygiene of restaurant, (4) location convenience, (5) interior of the restaurant, (6) service manner, (7) freshness of food, (8) types of food.
In the satisfaction-driver scale, the attributes followed closely though with significant variations: (1) reasonableness of price, (2) non-smoking area, (3) taste of food, (4) service manner, (5) special offers, (6) interior of the restaurant.
Of particular interest is the attribute, "non-smoking area" which appeared high in the satisfaction driver scale. The industry should take note of this consumer plea for fresh air when dining at fast food restaurants.
Other interesting statistics revealed in the survey: on average, respondents consumed 2.9 times lunch, 2.5 times breakfast, 1.8 times tea set and 1.7 times dinner per week at fast food restaurants; male tends to dine at fast food restaurants more frequently than female; and so are the younger consumers in the age bracket of 15-34.
Confusing signals inflating running costs of inkjet and laser colour printers
Users of inkjet printers often wonder whether they should continue printing when the "ink out" sign is on? Should they immediately discard the ink cartridge with ink still left inside, and replace it with a fresh one?
The answers to these and other questions bearing on the ink cost of running an inkjet colour printer can be found in a test report of the Consumer Council on 14 inkjet models.
Inkjet printers are these days relatively inexpensive ranging from $590 to $2,680 for the test models. But the test showed that the yearly ink cost could vary substantially from printer to printer.
On the assumption of a weekly output of 3 letters, 2 colour documents and 1 photo, the annual ink cost of the test samples could vary by as much as three times, ranging in estimates from $289 to $1,032.
So, the economical use of ink is rightly a matter of vital consideration to consumers. Highlights of the test results revealed the following:
- When the "low ink" sign is on, all samples could continue printing a number of pages with no visible change in quality, and depending on the model and the cartridge used, the number of pages could range anything from a minimum of under 5% more pages (2 models) and to a maximum of 50% (also 2 models).
- Consumers may continue printing after the "low ink" message is issued to prevent discarding cartridges too early. Indeed some models provide such useful information, in their "low ink" messages, as the percentage of ink left, number of pages that may be printed.
- Most samples could in fact print a few more pages even after the "ink out" signal appears. But consumers will do well to replace the cartridge if they are to print an important document or on expensive photo paper.
In addition to inkjet printers, the Council also tested 4 laser printers ranging in price from $6,390 to $9,890.
It was found that 2 of the laser samples could print over 40% more pages after the "toner out" sign is out.
According to a manufacturer, when the "toner out" message is displayed the print quality of the output cannot be assured due to lower remaining toner and the printer will stop. But if the users want to keep printing with lower print quality, they can do so by following the user manual instruction.
Another manufacturer asserted that their toner cartridges are "overfilled" to ensure there is sufficient toner to meet their stated lives; but maintained that the users should be duly warned that a toner cartridge is closely empty to ensure print quality - and prevent waste of time, paper and other consumables.
Latest survey results on price movements of major supermarket chains
The price movements of a basket of supermarket goods in the three half-yearly periods, from January 2002 to June 2003, under comparison have shown one increase and two decreases in average actual selling price.
The Consumer Council has conducted regular surveys spanning over 18 months in three separate periods, i.e. January to June 2002, July to December 2002, and January to June 2003.
The latest survey covering the first half of this year showed that when compared with the two 6-month periods last year the average selling prices have come down by 0.8% (January to June 2002) and 2% (July to December 2002).
Notable decreases were recorded in the categories of household cleaning products (4.7%), non-staple foodstuffs (3.9%) and rice (3.4%).
Nonetheless, a few categories of products had their prices adjusted upwards: notably, canned food (4.5%), edible oil (2.4%) and dairy products (2.4%).
The survey also covered the average list prices (which do not include discounts and other promotional offers) during these three periods under comparison.
It showed that the price movements in terms of average list prices recorded two increases and one decrease.
In comparison with the two 6-month periods last year, the latest survey showed that the average list prices have risen by 1.5% over the same period last year but decreased by 1.5% over the immediate preceding 6-month period.
The survey was based on prices collected from three major supermarket chains on a basket of 114 items of selected fast-moving-consumer goods.
Chairing the press conference today (August 15) on the publication of CHOICE issue number 322 is Prof. CHING Pak-chung, Vice-Chairman of Publicity and Community Relations Committee of the Consumer Council.