Last Thursday saw the third World Toilet Day, a little-known holiday. Although it was largely unreported by the media, I came across an article in your newspaper titled "Toilet taboo keeps us from discussing real impact of sanitation failures." Many people might find the idea of the day silly, but it's no joke; toilets are a serious and urgent issue relating to the health, safety, dignity and development of billions of people.

According to the UN, around 2.4 billion people in the world don't have access to decent sanitation and more than a billion have to practice open defecation.

One out of three women lacks access to safe toilets. This might seem hard to believe in the modern age, but many people still defecate in the same fashion their ancestors did: in open fields or pit holes.

The theme for 2015 is "Sanitation and Nutrition," the connection between which may be hard to understand for the vulnerable populations who are usually victims of poor sanitation. By defecating in the open, they pollute the environment they live in.

Contaminated drinking water, tainted soil and poor hygienic habits constitute major causes of diarrhea, worms and other problems that can trigger chronic malnutrition in children.

Furthermore, open defecation exposes women to greater risks of violence. It also has a direct link to education outcomes.

A lack of latrines across schools in poverty-stricken countries and regions has led many girls to avoid drinking water or even to drop out of school. It is estimated that girls' enrolment rate will rise 11 percent worldwide if there are adequate toilet facilities.

India is a pertinent example. India suffers from a severe shortage of lavatories both at home and in public places. More than 60 percent of Indians, most of whom live in poverty, have no access to private toilets and no power to change their fate.

About 70 percent of rural Indians are forced to defecate in the open. And it is said that for many Indian women, having a toilet at home has even become one of the standards of choosing spouses nowadays.

India's biggest travel app, HolidayIQ, concluded through an extensive survey that 99 percent of travelers in India called for more toilet facilities in tourist attractions and on highways. "Even at some of the world's most frequented sightseeing sites in India, access to toilets is considered a luxury," it claimed.

Another census in 2012 revealed that more Indian families own mobile phones than lavatories. But this twisted phenomenon actually reflects a common conundrum in many developing countries: While they are stepping into a modern world abounding with cutting-edge technologies, one foot remains in the stinking mire geared to the pre-modern age.

Fortunately, New Delhi has recognized the severity of the problem and Prime Minister Narendra Modi prioritized construction of more toilet facilities in his speech during last year's Independence Day. But it will perhaps take his government arduous effort to achieve this goal and change the rooted habits of the public.

It took the developed world a century to turn the first modern lavatory in London into a standard residential installation.

The UK had been rejecting suggestions to build public toilets until a cholera epidemic ravaged London in 1832 and staged a comeback in 1848, and the link to dirty water was proven for the first time. These plagues, which claimed more than 20,000 lives, prompted the birth of the first modern public lavatory in 1852.

George Jennings, English sanitary engineer and the inventor of public flushing toilets, once said, "The civilization of a people can be measured by their domestic and sanitary appliances."

It is fair to say that the history of toilets is the history of civilization.

Absence of toilets is a colossal international challenge and requires collaborative efforts on all parts to prevent repeated epidemics in India, Africa and many other places in the world. The most rudimentary human need should not become an obstacle for the development of civilization.

Wang Xiaonan, a Beijing-based freelance writer