Scores of Hong Kong parents took to the streets with their children on Saturday to demand that police stop using tear gas because of health risks, after more than 10,000 rounds were fired amid the months-long political unrest roiling the city.

More than 100 protesters, mostly wearing masks and dressed in black, marched peacefully from Suffolk Road in Kowloon Tong to La Salle Primary School. The action came after concerns were raised over dioxins released into the environment from the wide usage of tear gas.

Police said the turnout peaked at 130.

Holding posters and the hands of their young children, the parents chanted slogans such as “Protect children, the government is responsible” and “Disclose the composition of tear gas”.

Stephanie Sum Yi-ching, organiser of the police-approved march, said there were many prestigious schools along the route and she hoped officials would pay attention to the pollution caused by police.

“Police’s use of tear gas is really too much,” Sum said. “The tear gas residue is everywhere, even in schools or parks. It really affects our children’s health.”

The mother of two said her six-year-old daughter was affected by an unknown gas in Tuen Mun and suffered allergic reactions in her eyes for a week.

Sum was referring to a mysterious stench in the area in October, which residents claimed was tear gas coming from a police facility. There were complaints from people about skin, eye and throat discomfort.

In that incident – which sparked clashes between protesters and officers – police denied they were testing tear gas, with the government failing to find a source for the smell.

In recent weeks, another discussion over tear gas was sparked after a frontline reporter revealed he was diagnosed with chloracne – a skin condition linked to exposure to dioxins.

At Saturday’s march, occupational therapist Lam Bok, 34, said Hong Kong had become a “city of toxic gas”, adding his friend’s children experienced skin redness a day after they walked on streets where tear gas was released.

“It’s useless to fire tear gas. If it’s effective, the protests won’t last more than five months,” said Lam, who brought along his seven-year-old son, Moses.




William Lee, 50, who works in the financial services sector, admitted he was worried about the health effects from the chemical canisters, as the government had not disclosed their composition.

He said his family always walked around protest hotspots such as Yau Ma Tei, Mong Kok and Tsim Sha Tsui and hoped officers would not abuse the use of the non-lethal weapons.

In a reply to the Post on marchers’ demands, police said they used tear gas to create a safe distance and reduce direct clashes with protesters, making dispersal effective. The force also said officers had strict guidelines on using ammunitions and would take reference from information provided by manufacturers to ensure the weapons were deployed in a safe and normal manner.

On Wednesday, Secretary for Food and Health Professor Sophia Chan Siu-chee said the Department of Health and the Poison Information Centre under the Hospital Authority found no literature or scientific evidence on dioxin-poisoning cases caused by the use of tear gas.

But she refused to reveal the composition of the chemicals, saying it would be “inappropriate” to disclose procurement details of the equipment used by the force, as that would “affect police’s operational capability”.



Professor Chan King-ming of Chinese University’s school of life sciences insisted there was no evidence proving the firing of tear gas would release dioxins.

“I don’t believe that tear gas, even when burning at high temperatures, can produce dioxins,” he said.

The academic and the university are testing a total of 20 soil samples to find out if volleys of tear gas shot on campus in fiery clashes this month had raised chemical levels there. Last Tuesday, more than 1,000 rounds of tear gas and rubber bullets were fired at students who responded with hundreds of petrol bombs.

From the preliminary test results of two samples, Chan said a dioxin-like compound – commonly found in soil samples – was detected, and the level was within the acceptable range for residential areas. He added the most toxic variation of this compound, usually generated from the burning of waste, was not found.

The Sha Tin university said it had received initial test results on campus soil and found no cyanide in the samples. All offices at Chinese University would resume operations on Monday.