Many towns are blanketed nightly with the gas, raising fears of cancer and other long-term health problems.

Ma’ameer, Bahrain – Shoqqi Abdulnabi’s daughter, Zainab, was born three months premature; she was healthy but frail when he brought her home in March of last year to this village, a cheerless warren of concrete buildings in an industrial area just outside of Sitra. Weeks later, she was blind.

The village, like so many others in Bahrain, has become a flashpoint for clashes between riot police and angry protesters, signs of which were evident on a visit earlier this month. Makeshift barricades – branches, large rocks, dumpsters – lined the roadside, ready to be pulled into place on short notice.

Residents had gathered more than twenty empty tear gas canisters near the entrance to the village. They were all from the previous night, one resident said, though his claim could not be independently verified. The sharp, sour smell of the gas lingered in the air.

Abdulnabi blames the almost nightly tear gas for blinding his daughter, now almost 18 months old, and for causing a range of other health problems, including asthma.

“Two weeks after her discharge from the hospital, there was so much toxic gas in this area, so much of it that she suffocated,” he said. “I thought my daughter would die. She wasn’t able to breathe. She choked.”

Abdulnabi took Zainab to the hospital in Sitra, which referred him to Salmaniya Medical Complex, the largest hospital in Bahrain. She spent a week there; Abdulnabi said he was afraid to visit her because of rumors that police were arresting people inside the hospital.

So it was only after her discharge that he realised his daughter was blind, a diagnosis he said the doctors refused to acknowledge. “None of the medical staff would give us a report that my daughter was blind, we could not prove anything,” he said. “This was caused by the wrongdoing of the government… and they won’t take responsibility.”

Excessive tear gas

Short-term exposure to tear gas can cause pulmonary edema, adult-onset asthma, skin blistering and other serious conditions. Little is known about the long-term effects of the gas, in part because it is so rarely used on a long-term basis.

The minimal research that exists suggests tear gas could indeed be responsible for Zainab’s blindness. Health departments in the United States warn that long-term exposure in a confined area – defined as more than one hour – can cause blindness. That’s because tear gas can damage the optic nerve, which transmits information from the eye to the brain.

Abdulnabi took his daughter to India last year for medical treatment, and doctors there indeed attributed her blindness to a neurological problem. “The doctor there said it’s not a problem of the eyes, but a problem of the brain, the nerves,” he said.

Rights groups say that at least 25 Bahrainis have been killed by excessive tear gas inhalation – roughly one-third of the people killed since widespread unrest began here last February. (Some groups, like Physicians for Human Rights, put the number slightly higher.)

That figure does not count the three protesters killed after being shot with tear gas canisters. Nor does it include at least two potential cases where medical evidence was inconclusive, including activist Abbas Jaffar al-Shaikh, 26, who died from cancer last year. Studies on the cancer-causing effects of tear gas have been inconclusive.

The Bahrain Independent Commission of Inquiry report, released in late November, faulted security forces for their “disproportionate use of tear gas for the dispersion of protesters.” But the use of tear gas has only increased since then: 18 of the 25 deaths occurred after the report was released.

Many villages in Bahrain are now sprayed with the gas several times per week. At times it seems much of the country is affected: On a recent evening, Budaiya highway, the main east-west thoroughfare outside Manama, was blanketed with gas from clashes in several villages which sit along the road. Patrons sitting outside at a coffeeshop had to take shelter inside.

John Timoney, the former US police chief hired to consult with Bahrain’s police force, blames the increased use of tear gas on what he described as increasingly violent protesters.

“There’s a complaint that there’s excessive tear gas,” Timoney said. “What I’ve observed is a huge increase in the number of Molotov cocktails being thrown at police officers, night after night.”

‘They’re trying to hide what they’re doing’

But many people here accuse the police of shooting tear gas not just at protesters, but inside of private homes.

Several high-profile Bahrainis – including Nabeel Rajab, the head of the Bahrain Centre for Human Rights, and Ali Salman, the leader of Al Wefaq, the largest opposition party – have had their homes attacked in such a fashion.

“They deliberately shoot them inside the houses, because they want to create a problem between the protesters and the people who are not protesting,” said one activist in Abu Saiba, a village outside of Manama. “They want to drive a wedge [between them].”

Residents in Bahrain’s villages also say the government has started using a new chemical, CR gas, which is significantly more potent than the CS gas typically used against protesters. Physicians for Human Rights documented cases of patients with “atypical symptoms, including non-epileptic seizures and hysteria”.

“The tear gas canisters, they used to be from the USA and India,” said a protester in Sitra who asked that his name not be used. “But these new ones have no labels… they’re trying to hide what they’re using,” he added, holding up an unmarked canister which carried no country of origin or other identifying information.

The allegations about CR gas, and more generally about any new chemical, cannot be independently verified. Several Bahraini police officers declined to comment on the chemical being used, and the health ministry has barred doctors from examining the content of tear gas canisters.

If the police are indeed using CR gas, again, little is known about the long-term effects. Anecdotal evidence suggests it can cause serious illness: The Egyptian riot police saturated downtown Cairo with CR gas for several days in November, and hundreds of protesters and journalists reported respiratory problems and other ailments.

Residents of the hardest-hit villages have tried to protect their homes as best they can: Abdulnabi says he places wet towels under the doors at night, and he purchased an oxygen tank for his daughter. But they worry about the long-term impact of a gas whose effects the government has not fully researched.

“I’m used to it now… the suffocation is on a nightly basis. In the morning new air comes in,” said Abdulnabi, cradling his daughter. “But what about the future? What about the consequences of being tear-gassed daily?”