Staff at schools built on a former landfill site, where four teachers contracted bladder cancer, are starting strike action over health concerns.

Significant concerns have been raised about Buchanan and St Ambrose High Schools in Coatbridge, North Lanarkshire, after the drinking water was tested because it was blue.

Buchanan High was closed to pupils on Thursday after teachers began strike action - which will run until Friday 28 June.

Members of the NASUWT union at St Ambrose High will strike from Tuesday until Friday next week.

It comes after the Scottish Government set up an independent review to help address the fears of parents and teachers that harmful waste chemicals were to blame for the development of cancer.

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Copper in the drinking water and elevated levels of arsenic in the blood of people attending the schools are also to be the focus of the inquiry.

But North Lanarkshire council has insisted the schools and the site are safe.

Paul Cackette and Margaret Hannah, who are leading the review, met the heads of both schools, as well as public health experts and other representatives from the council on Wednesday.

Chris Keates, general secretary of the NASUWT, said: "Our members are suffering deep stress and anxiety about their health and welfare due to the failure of their employer to take the necessary action to provide assurances about the safety of the site.”

She added that the independent review was a “welcome development” but it does not commit to a full comprehensive site survey which tests the water, air, soil and fabric of the building.

"Teachers are deeply anxious about whether there is any link between conditions at the school, including the blue water and a range of health issues among staff,” Ms Keates said.

The union leader wants a site survey to be commissioned immediately and for the schools to close early to give teachers “respite from the daily anxiety of having to attend the school site.”

Gerard McLaughlin, head of education at North Lanarkshire Council, said there is no evidence to support a link between blue water at the school or the site itself and any serious ill health.

On the strike action, Mr McLaughlin said: “We understand the impact that this will have on pupils and parents at Buchanan High School as a direct consequence of this action.

"Having assessed the potential impact, we have regrettably decided that Buchanan High School will be unable to receive pupils during the period of industrial action due to the specific medical needs of some of the pupils.

"Neither the school nor the council would ever take any risks with young people's safety.

"Despite our disappointment that the NASUWT has taken this decision, we will remain in dialogue with trade union officials over the coming days."

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The review is tasked with looking at specific health and safety concerns raised at the shared site, as well as the history, construction and maintenance of the campus.

It will examine health concerns, including possible exposure to unspecified chemicals in the water resulting from previous land use at the school site, to see if these are linked to developing cancer.

More than 16,000 people have signed a petition calling for an investigation and for staff and pupils to be tested for toxins.

The probe is set to be completed "as soon as practicable" and ahead of the next school year.