World Water Day has been marked in Nanjing by local media turning it into an opportunity to put pay to a number of rumours regarding the resource, rumours so pervasive they are taken by many to be absolute fact.
Yesterday, 22 March, marked World Water Day, the annual celebration of respect to our planet’s most precious resource that has been held annually since 1993. This year, the conversation had been all about what water means to people in different settings.
In China, water is no less important than anywhere else. But it can be manifest in culture in different ways. For example, the expression ”有山有水” (has mountains, has water) is a catch all to indicate the auspiciousness of a particular place. Others, such as “如鱼得水” (like a fish in water) might be common across cultures.
While many such expressions or beliefs might be grounded in fact, others are less so. And it is these that Chinese media has chosen to call out this World Water Day.
Rumour 1: Drinking Yesterday’s Water Gives You Cancer
Rampant on WeChat and especially popular with the elderly, the rumour states that the left-over boiled water from yesterday, or water boiled multiple times, contains nitrite, which is a carcinogen.
According to Fan Zhihong, Associate Professor in the School of Food Science and Nutritional Engineering at China Agricultural University, ordinary drinking water contains only minerals and trace elements. As a result, carcinogens will not appear out of thin air, joked Nanjing Daily yesterday.
As long as the water source meets standards, theoretically, no matter how many times it is boiled, it will not produce carcinogens.
“You don’t have to worry about excessive nitrite in overnight water and repeatedly boiled water”, said Ruan Guangfeng, of the Kexin Food and Nutrition Information Exchange Centre, in an interview with Science and Technology Daily.
Rumour 2: Drinking Four Litres of Water Every Day is Poisonous
Feeling cold? Drink water. Headache? Drink plenty of water. In a bad mood? Drink more water. In the eyes of many a Chinese, a glass of H2O is the perfect cure for an endless array of ailments. But can it be too much?
When the quantity of water consumed by the human body greatly exceeds the amount discharged, water poisoning may be the result, also known as hyponatremia. This results in sodium in the body becoming diluted. According to the Mayo Clinic, “When this happens, your body’s water levels rise, and your cells begin to swell. This swelling can cause many health problems, from mild to life-threatening”.
But while water poisoning is technically possible, it rarely occurs in clinical practice. In cases where it does, it is not only due to the excessive drinking of water, but also to underlying health issues, such as kidney disease. “As long as you don’t drink it [4 litres] in a short time, it won’t affect your health”, said Ruan.
Rumour 3: Drinking Hard Water Gives You Kidney Stones
After a kettle is used for a long time, scale will form on its inner wall. The phenomenon is especially prevalent in hard-water areas such as northern China. Being in the middle of the country, Nanjing’s water is neither hard nor soft. It may taste bad, but it doesn’t harm your health.
According to a 2018 study published by the Korean Urological Association, most of the large, long-term studies show no or very little relationship between hard water and kidney stones. For the general population, there simply is no increased risk associated with drinking hard water.
On the other hand, kidney stones can be partly the result of not drinking enough water. In actual fact, hard water is rich in calcium and magnesium, and therefore, in this sense, drinking hard water can also supplement the body with additional minerals.
The Healthy Way to Drink Water this World Water Day
According to the Nutrition Dietary Guidelines for Chinese Residents (2016 Edition), adult men should drink 1.7 litres of water per day, and adult women 1.5 litres. These amounts should be adjusted according to people’s own situations. Do a lot of exercise and sweat more? Drink more. Live in the north where the air is dry? Drink more.
In general, between six and eight glasses of water per day ought to be sufficient. Experts also advise us to drink small quantities frequently, and not to wait until we are thirsty before lapping up nature’s most valuable resource, on World Water Day, or any day.
