For most of us, the library is a source of books and information. The core factor of the work of a librarian is absolutely vital and should never be forgotten. But something else is happening in our libraries, with repercussions for library workers.

I worked for a long time in public libraries and most of my day was not spent shelving books (or reading them). As much of my time was spent dealing with human beings as printed volumes. A passion for books and reading first drew me to library work, but empathy, belief in human rights and the importance of social activism kept me working in them. I’ve worked in libraries of all sizes, from large city ones to tiny mobile ones, but what they all had in common was how much they meant to the most vulnerable in their communities.

One day a week, my mobile library stopped at a small rural community based around a bus stop. My first visitors of the day were three older women who only left the house to come to the library. I was the first person they’d spoken to all week; sometimes I was the only person they would speak to all month. I put the kettle on, and we chatted.

The next person to drop in was a young mother feeling overwhelmed by her new life. Stuck at home alone all day with her baby, the only thing she had to break up the week was her visit to the library. More than once she told me that the only reason she had got out of bed was because the library was coming. It gave her a purpose and coming to get her favourite books while talking to someone meant the earth to her. I put the kettle on, and we chatted.

Around mid-afternoon, a widower came by to borrow a big pile of books. He was cripplingly lonely. He said he just liked to hear the sound of a woman’s voice. He missed his wife so much that a life without the sound of her voice was too much to bear. I put the kettle on, and we chatted.

‘The next person to drop in was a young mother feeling overwhelmed by her new life.’ Picture posed by model. Photograph: Alamy

None of these people would dream of reaching out for formalised social care, and the sad fact is that it’s unlikely that any of them would have received help had they done so. They didn’t think they had mental health needs, but there is a good chance that many of us will need extra support at some point in our lives. What is available for us when we do? There is really only one place in the community where people can receive that sort of informal help to get over a tricky patch in their lives, or to help them navigate an increasingly stressful world – and that’s the library. In 2017, my local authority cancelled all of its mobile libraries, saying that there was “no significant demand”, and all the library workers lost their jobs.

Austerity has added an increasingly problematic element to this informal social care. As community services such as drop-in centres and social support facilities are axed, the people who relied on them have been cut off. This means that vulnerable people with complex mental health and/or addiction issues are set adrift and in many areas the only thing that remains open to them is the library.

One library I worked in was around the corner from a residential mental health unit that had been closed because of the shift to “care in the community”. These vulnerable adults had nowhere else to go during the day, and so they came to the library. A month after the unit closed, a colleague was stabbed in the arm by an emotionally disturbed former resident of the home. On Monday morning, she was back at work and planning support sessions for other displaced residents of the unit in order to help them safely transition back into the community.

Every time a service is cut in a community, the public library has been expected to pick up the slack, but library workers have had little or no training in this and their own mental health is suffering. There are fewer and fewer of them, and many are now single-staffing libraries, while their own support networks have gone. Every day I’m contacted by library workers at the end of their tethers as they try to help people in their communities who have effectively been abandoned by the lack of available social care.

I’m on the verge of tears and looking for another job. We have no voices for fear of losing our jobs and pensions.

One email I received from a library worker said: “I’m physically and mentally exhausted doing a job that seems to expand on a monthly basis. In the past month, I have been verbally abused and have had issues with a library user with mental health issues such that I worry for their safety. I’m on the verge of tears and looking for another job. We have no voices for fear of losing our jobs and pensions.” This is just one of the many messages I receive every week.

Every day, library workers are quietly changing and saving lives. As well as providing informal mental health and wellbeing support, they are raising national literacy levels, supporting families and reaching out into their communities to make them stronger and more cohesive. Now picture what your communities would be like without those library workers. For many people they are literally the last line of mental health defence.

Since 2005 we have lost more than 10,000 library workers and more jobs are being cut all the time. Hundreds of libraries are being handed over to volunteers or are being left unstaffed. As a nation, we are not only haemorrhaging libraries but the highly experienced people who work in them. If we lose library workers, we are at risk of completely abandoning those people in our communities who just need someone to talk to, someone non-judgmental who can offer a helping hand, or maybe just a patient ear. Formalising what was once informal social care is expensive, and so is the failure to support mental health, and that will cost us all a great deal more than investing in library workers ever would.

• Dawn Finch is a children’s author, librarian and library activist. She is a trustee of the Chartered Institute of Library and Information Professionals (CILIP)