Teachers from a second school hit by a health scare are taking strike action over the concerns.

Since the 2012 opening of Buchanan High and St Ambrose High in Coatbridge, North Lanarkshire, four former or current teachers have all been treated for bladder cancer.

In addition, the campus has also been the subject of a drinking water scare after the supply turned blue.

READ MORE: Pupils at health scare school 'should be tested'

Health experts say the cancers are not linked to the school because staff were not there long enough to have contracted the disease.

They also argue safety sensors at the school would have picked up any leak of toxic materials from the landfill site.

And the council says the blue colouration was a result of water lying in copper pipes before the school opened and is not dangerous to health.

However, members of the NASUWT teaching union at Buchanan High decided to take strike action earlier this month and now staff at St Ambrose are joining them.

The NASUWT is calling for a full site survey and early closure of the school campus to enable the work to start.

READ MORE: Teachers at Coatbridge schools to take strike action

Chris Keates, general secretary of the NASUWT, said: "Members at St Ambrose are joining the strike action as a result of the continued failure of North Lanarkshire Council to take action to address the deep concerns of the teachers at the school over health and safety, concerns which are shared by parents and the whole school community.

“We are continuing to press the council for an expert full site survey, including air, water, soil and tests on the fabric of the building to be carried out immediately, and for early closure of the schools on the site to remove the teachers and pupils from potential continuing harm and protect their health and safety."

This week, the headteacher of St Ambrose insisted her place of work was safe and had not caused the spate of bladder cancer cases.

READ MORE: Headteacher says 'blue water' school is safe

Ellen Douglas told the Herald on Sunday parents should to listen to experts who refute any cancer link.

The Scottish Government has already begun an independent review of the health and safety concerns.