It would be "extremely difficult" to complete an in-depth investigation into the two Coatbridge schools built on a toxic landfill site during the six-week summer break, a public health expert has warned.

Speaking to Scotland Tonight, Professor Andrew Watterson of Stirling University's Occupational and Environmental Health Research Group called for "more resources and staff" to go into the inquiry to reassure parents that it will be safe for their children to go back to school after the summer holidays.

The professor was in discussion with The Sunday Post journalist Marion Scott and SNP MSP for Coatbridge and Chryston, Fulton MacGregor.

Here is an edited transcript of professor Andrew Watterson's responses.

John MacKay: Professor, are there grounds for concern there?

Andrew Watterson: I think there are. There are grounds with regard to how the information is being communicated. There are problems with, I think, transparency, and there are also issues about trust. All those three things have run into each other. So it's very difficult to identify, on the basis of the information we've been given, exactly what the risks are. We know what the hazards are, we know what the risk could be, but it's not been documented properly.

John: Although there is no evidence, we have four teachers in one school, three of them indeed in one corridor, who have a very rare type of bladder cancer. Is that not in and of itself evidence, or some evidence?

Andrew: It looks as if there is. It's a prima facie case that there is a problem and you could go to other countries and see how these clusters had been investigated, and you could find the information you need. At the moment, that information isn't coming back from the health board. We haven't seen the details about the age, the gender, the sort of previous history. Whether there's a smoking history, and so on, relating to this particular cluster. Nor, as far as I'm aware, has there been any environmental monitoring done in the site they are in.

We are told [by NHS Lanarkshire] that a 10 year latency period is the one to go for. The schools have only been up seven years, so there can't be a problem. Yet you could go to the US and you could find short latency periods of four years with regard to this particular cancer. It doesn't mean that there is a cause there; it means that at the moment we can't tell it's been properly investigated. And in that context, I think the review, although very helpful, doesn't answer the issues for the parents. Because what you should be seeing is informed parents, parents who are consulted. But another element is that they participate in the investigations. So I think the calls for an inquiry to see what's happening now and in the future, as well as looking back, are really part of the picture.

John: There are calls for the school to be closed early. But even if that happened, that's eight weeks, including the six-week summer break. Is that enough time to carry out an investigation?

Andrew: I think it would be extremely difficult to carry out an in-depth investigation, even looking at the information that is in the public domain, it's very time-consuming to go through it. It's worth bearing in mind that we're talking about four problems that have emerged. There's the building on the Brownfield site, there is then the blue water problem, and there is then the cluster, or alleged cluster. And there are then the concerns about some of the children's health linked to possible consumption or ingestion or inhalation of a number of other substances. So there are four elements there that are problematic. And I think that's why the parents and the staff need to be fully involved in this. It's not a case of patient confidentiality, by the way. Because certainly from the staff point of view, if the staff are happy that these things be investigated, that's not an issue. If the parents are happy to talk about the problems that they think their children have, that's not an issue. Yet we're faced with an irony here, because the review panel will see information from the council and from the health board that the parents and the staff have not yet seen. That can't be right.

John: Should the school be closed, first and foremost? And if so, how long do you think would be necessary?

Andrew: I think there needs to be a thorough examination of all the information we've got and further monitoring. I think if the school is going to close anyway for the holidays in the next two weeks, I don't think there will be any immediate problem there. So I would suggest that more resources and possibly more staff go into the inquiry when the school shuts for the holidays, so that the parents can be sure when they come back that there's not a problem.