It was around noon and we were sitting in a community centre of sorts in Shuafat refugee camp, located to the northeast of Jerusalem. Two residents of Shuafat burst into the building, their eyes streaming as the tear gas used by the Israeli forces began to have its desired effect.

We looked out onto the street, empty of the hustle and bustle that I’d walked through just ten minutes earlier. Isam and his nine-person team of volunteers seemed less than startled by the events, recalling that the same thing had happened just yesterday. “They are not here to arrest anyone,” they reassured, “for that, they come in the night.”

They took out mobile phones and began filming and taking photos of the Israeli border police who were issuing fines to cars parked on the road below. At 500 shekels (about £100) per car, Isam called it “a form of income for the occupation.”

Isam resumed telling me about his new study entitled Widespread problem of drug abuse in the West Bank, despite the occasional sound bomb being thrown by the Israeli forces on the street outside. Conducted in centres in Al-Khalil (Hebron), Nablus, Gaza and Shuafat camp, it aims to provide an updated insight into the number of drug users and addicts, as well as the prevalence of diseases related to drug abuse in the West Bank.

Unlike neighbouring Egypt and Lebanon, Palestine has no historic connection with the drug trade. However, research has shown the situation changed after the Six Day War, with the occupied territories becoming fertile ground for the smuggling and using of all types of illegal substances.

“When the occupation began in 1967, something new happened in the country,” said Isam. “We were a poor and closed community. People began to work in Israel and earn good money in construction and industry. With this came club nights, freedom, sex and drugs.”

According to a Palestinian Central Bureau of Statistics study carried out in 2007 and updated in 2011, there are 80,000 drug users and addicts in the occupied Palestinian Territory, including East Jerusalem and the Gaza Strip. Isam stated that about 20,000 of those are addicts. He estimated that a third of drug users are in Gaza, a third in the West Bank and a third in East Jerusalem, with about every 1 in 10 citizens in East Jerusalem using drugs.

Isam believes that political reasons and Israeli policy are to blame for the high number of drug abusers in East Jerusalem. “You can see that dealers feel free here,” he said. “Drugs are a weapon to continue the occupation. [Israel] knows that those using drugs will not resist the occupation.”

Shuafat camp has become a hotbed for drug abuse. Established for Palestinian refugees in 1965, the camp fell under Israeli jurisdiction after Israel annexed the whole of Jerusalem in 1967, a move the international community did not recognise.

Since 2003, the camp has been surrounded by a 25-foot concrete wall interspersed with watchtowers, that cuts the occupants of Shuafat camp off from the rest of the city and can only be accessed via a military checkpoint.

Due to the Israeli Ministry of the Interior’s policy of revoking Jerusalem IDs from Palestinians who do not have their “centre of life” in Jerusalem, the camp has become extremely overcrowded with Palestinians who might not otherwise afford the high living costs in Jerusalem. Nowadays, it is estimated that between 60,000 and 80,000 people live in the camp.

Despite paying their share of municipal taxes, Jerusalemite Palestinians receive a fraction of the services of Israelis in the West of the city. There are few health facilities, schools are poorly funded and overcrowded, rubbish is rarely collected and water shortages are a frequent occurrence.

Following his own history of drug addiction, Isam managed to get help and has since remained drug-free for 27 years. He has dedicated these years to working in the field and helping others, and is now the Awareness Centre Manager for Al-Maqdese (Arabic for Jerusalemite) for Society Development. “Nearly all the addicts know me personally or know of me. They trust me; I have a good name. This is my message in this life, to help people. I am the person people come to for help.”

Al-Maqdese conducted two similar studies in 2010 and 2013 and found high numbers of disease attributed to the sharing of needles. This was the catalyst for their harm reduction programme – a mobile centre handing out clean needles and condoms to drug addicts. Isam and his team also arrange awareness-raising workshops to tackle the drug problem in schools.

The current study works through an incentive scheme in which each participants is paid 50 shekels (about £10) and given coupons to invite three friends to take part in the study. Isam wants 300 participants from Shuafat, which he predicts will take one month, and is hoping to have the results for the study by April.

Isam was expecting about 15 people to sign up for the study that day but was resigned to the fact the that the Israeli Forces storming the camp would probably prevent that. “People are too scared to come out now,” he said. Two men enrolling for the study as the raid began had already fled.

One of the volunteers helping to interview the participants, Mahmoud, is an ex addict. He began smoking hashish at the age of 12 with his friends. Beaten by his parents, he left home at an early age and began using different drugs, including during his stints in prison. “Heroin was my favourite. The tenth time I was in prison, a social worker asked me if I wanted the chance to make something of my life and I took it. I’ve been clean 13 years now. I’m married; I have six children and my own taxi company,” he said, adding that he met Isam when he was an addict and used to talk to him once or twice a week. “Now, I like to help others facing the same troubles I faced. It’s my duty,” he added.

We once more heard a commotion outside and watched as a tipper lorry with a crane took down a banner. Hanging above the street, the banner had been an invitation to residents to attend an upcoming wedding. The team grinned at this seemingly trivial exercise.

Isam has noticed many changes in drug usage in the West Bank. In the past, drug users tended to be between 27 and 37 years old but now, he stated, “Most of them are less than 20 years old.”

The introduction of synthetic cannabis several years ago has proved to be a major problem in tackling drug abuse for Isam and his team. Supposed to mimic the effects of THC, the main active ingredient in marihuana, synthetic cannabis is much more nefarious. Its street name in Palestine is “Hydro” or “Mr Nice Guy” (known in other countries as “Spice” or “K2”).