At a day service center for elderly individuals in Usuki, Oita Prefecture, a sports drink seemed like a prudent beverage on a summer day. 

However, 13 elderly citizens got sick after gobbling the mixture of sports drink powder and water from a kettle.

An analysis revealed copper in the kettle fur, or flaky deposits of calcium salts that accumulate on the bottom and sides, had dissolved into the beverage and caused the acute poisoning.

The case is among a succession that have been reported where people become ill after consuming water and food in this world’s most hygienic country.

Behind the trend, according to an expert, is consumers’ lowered awareness of the issue.

COPPER ACCUMULATION

At the day service center in Usuki, tap water was boiled and then cooled before mixed with the sports drink powder

The finished beverage was distributed to the facility’s users ranging in age from 77 to 96 following bathing on the morning of July 6, according to the prefectural government. 

After consuming the drink, those sickened reportedly complained of such conditions as nausea and loose bowels. Informed of the incident, the local public health center examined the drink and detected 200 milligrams of copper per liter in it.

Although the kettle was made of stainless steel, fur had accumulated in the 10-year-old vessel, turning blackish in a section in the kettle, according to the results of the health center’s inspections.

A tiny amount of copper in tap water that formed the fur in the kettle is thought to have dissolved in the acidic sports drink.

WORLD’S SAFEST WATER

Koichiro Fujita, a professor emeritus of medicine at Tokyo Medical and Dental University, who has surveyed water quality in 90 countries all over the world, described the case as being “unlikely” to occur under normal conditions.

As only an extremely small volume of copper can be found in tap water, the metal’s residue is easily washed away from dishes. That means, Fujita argued, it is rare that tap water is identified as the cause of poisoning.

Efforts to improve the quality of water supplied for consumption started around the beginning of the Meiji Era (1868-1912) since cholera spread through water during the Edo Period (1603-1867). Tap water in Japan is now deemed as boasting “one of the world’s safest qualities.”

Fujita, however, noted that mineral water is better for “direct consumption.”

Fujita said although Japan’s water contains a smaller amount of chlorine for sterilization than the safety guidelines of the World Health Organization (WHO) and thus could not have significant negative health effects, different hardness levels are better for consumers with varying conditions.

“Those with diabetes and increased blood pressure should choose harder water, while soft water is better for children and others,” Fujita said. “Select different mineral water products, depending on your condition, to control your health. One can easily suffer from food poisoning when health conditions are not good.”

CONSUMERS’ LOWERED AWARENESS

Miso, vinegar, soy sauce and umeboshi were traditionally actively used to stop microorganisms from proliferating in foodstuffs. But consumers are currently said to have little awareness of food poisoning.

“People have lower awareness of protecting themselves, as salt-reduced products are pitched amid the health boom and advanced logistics systems are introduced,” said Makoto Kanauchi, a professor of environmental adaptation at Miyagi University.

Kanauchi recommended ingredients be heated, and miso and salt added to prevent foods from rotting during the summer.

According to the health ministry, 13,000 individuals became ill after consuming foods last year. About half were infected with the norovirus, but many other causes, such as bacilli, parasites, chemicals and natural toxins, were also detected.

In particular, a fish parasite known as anisakis has been confirmed as the cause of a growing number of poisoning cases.

Food poisoning can also occur even when consuming items generally viewed as safe. In one such case, children who ate harvested potatoes at an elementary school in Takarazuka, Hyogo Prefecture, last year were sickened due to solanine, a natural toxin in the vegetable.

Zucchini, bottle gourd and other cucurbitaceous plants sometimes boast significantly high bitterness levels, leading to vomiting and other health-related problems. Hydrangea leaves are poisonous though they resemble perilla in appearance, so one should pay careful attention when using the leaves for decoration.

People increasingly often carry their own shopping bags with them as store operators now charge for plastic bags to cut down on plastic waste. As juice from meat and fish could allow bacilli that may cause poisoning to proliferate, reusable shopping bags should be washed frequently.

Kanauchi pointed out that as consumers increasingly take food products out during the novel coronavirus pandemic, they should take precautions such as not buying at shops that sell food outdoors for many hours on hot days.