Scientists have been examining recent blood samples collected from wild polar bears and compared them with samples from the same part of the Arctic which were taken back in the late 1980s and early 1990s.

Now they found that significantly more of the recent blood samples contained indications that the animals had suffered from infections.

Let's talk more about this with the lead author of that particular study, the research wildlife biologist with the Alaska Science Centre, Dr Karen Rode, who's been studying polar bears actually since 2006, so very experienced in this field.

And this is quite alarming, isn't it, this research?

Yes, we definitely saw increases that were higher than has been seen in other parts of the Arctic in terms of the proportion of bears that were exposed to different pathogens.

So what sort of results have you found?

Just talk us through some of the details of this.

Yeah, so we looked at six different pathogens and specifically what we were looking at is antibodies in polar bear serum, which indicates whether or not they were ever exposed to that particular pathogen.

And then comparing between the two time periods, we were seeing increases in five of the six that we looked at, and some of them were more than doubling over time.

So twice as many bears are exposed to those pathogens than they have in the past.

And those changes appeared to be associated with increased land use by polar bears in response to sea ice loss, but also changes in the exposure of their prey that then gets transmitted up the food chain.

So it sounds really like the whole Arctic ecosystem is changing and changing for the worse as far as these bears are concerned.

Yeah, I mean, I think it's important to note that this population appears to be a healthy population overall, so the population isn't declining.

So we don't think that these pathogens are necessarily causing, we don't know, we don't have any evidence that they're causing disease in polar bears, which is actually really hard to detect in these animals that range really far out in remote areas.

But we know the population is healthy, but it does mean that as an apex predator at the top of the Arctic food chain, changes that we're seeing in their exposure indicate changes in exposure to other species across the Arctic.

And presumably this is something that's just going to keep getting worse and worse as a problem as climate change continues, as global warming increases.

I think, you know, this is certainly evidence not only in our population, but in two other polar bear populations, that exposure is changing.

You know, the question is, what's the impact of that exposure?

And a big message from our study has been that there's a need for increased surveillance of exposure to an Arctic environment because there's potential changes in the distribution of these pathogens.

And were you surprised by the results of your research?

Well, I think, you know, seeing, having known that two other populations had seen increases in pathogen exposure, I think to some degree we expected that that would probably be the case.

Certainly the changes were higher than we expected, but I think it's consistent with previous research in other populations.

All right.

Well, Karen Rhoad, thank you very much indeed for being with us with that alarming evidence really about polar bears in the Arctic.

Karen Rhoad there, research wildlife biologist with the Alaska Science Centre.

Thank you.