Rising temperatures, volatile weather, more floods, more droughts: climate change is going to affect our lives in many ways – but what about our health? The Intergovernmental Panel on Climate Change expects that overall the benefits to health of climate change will be ‘outweighed by the negative health effects of rising temperature’ - a view echoed by many experts.

Prof. Andrew Haines, Dir. London School of Hygiene and Tropical Medicine: I think in aggregate, in the round there’ll be an adverse impact overall on public health and that would be felt most strongly in low income countries.

What’s going on? How will climate change affect health? Earth Report investigates.

The Instituto de Salud del Niño is the largest public hospital for children in Lima, and a centre for children’s health studies. Here medical researchers believe they’ve identified a link between rising temperature and a life threatening condition. Mrs. Escarcena has brought her baby girl Maria to the emergency room because of high fever and severe diarrhoea. Diarrhoea is a leading killer of children in the developing world.

Dr. William Checkley, Johns Hopkins School of Public Health: Diarrhoea … refers to watery stools passed in an increased frequency and it is associated with severe dehydration and even death… many bacteria, viruses and parasites cause diarrhoea all through different mechanisms. Infectious diarrhoea kills 2.5 million children under five each year worldwide. That is five child deaths per minute.

Most of the diarrhoea cases end up in the oral re-hydration unit for treatment. Doctors need to assess baby Maria and decide on the best way to rehydrate her. A patient’s dehydration status is quickly evaluated.

Dr. Dante Figueroa, Instituto Nacional de Salud Del Niño: Diarrhoea is one of the common problems in the child population in Peru. If the patient has some dehydration, we put on plan B… when the patient is with shock … hyperbolic shock we put in intravenous therapy… it is named plan C. a lot of patients need only plan A and B. A few patients only plan C.

Baby Maria was is severely dehydrated by her diarrhoea and needs ed intravenous therapy liquid urgently if she is to survive. In the many shanty towns of Lima, there is poor hygiene and limited access to water. It is easy for children to get diarrhoea.

Dr. Robert Gilman, Johns Hopkins School of Public Health: People have what people call a cistern, where they will bring water… problem is if you notice, that’s open… people’s hands go in that, and there it becomes contaminated with faecal material from their hands. Especially since they can’t wash their hands after going to the bathroom because there are huge limitations on water.

Rising temperatures lead to more diarrhoea cases.

The summer heat helps encourages bacteria to grown. More bacteria, more diarrhoea cases. What if there was an increase in temperatures hot weather were driven even higher by global warming? What would the health impact be? Whenever Lima experiences an el Niño weather phenomenon it can drive temperatures up by as much as five degrees Celsius. El Niño is a re-occurring atmospheric and oceanic weather event that makes an appearance every three to four years. It starts with the Pacific Ocean warming up in the area of Indonesia, around Sumatra and Java.

Wilar Garmard Molina, President, SENAMHI: And then this water warms up the entire tropical Pacific Ocean… and eventually it arrives to the coast of South America, mainly to the coast of Peru and Ecuador. When this warming reaches a certain threshold … in temperature … adverse atmospheric events could happen, mainly heavy rains in our coast.

When an el Niño arrives in Lima the oral re-hydration unit becomes overwhelmed with sick children.

Dr. Dante Figueroa: The last twenty years of this oral re-hydration unit we saw approximately three El Niño phenomenon. But the worst was in 1997-98, we saw very clear the association between phenomenon El Niño and the number of admission to this unit with acute diarrhoea disease.

A girl in the rehydration unit.

Dr. William Checkley, Johns Hopkins School of Public Health: We studied the relationship between the unusual rise in temperature associated with the 97 El Nino and the occurrence of infectious diarrhoea in children in Peru.

Dr Robert Gilman: They had fantastic statistics on all of their cases for at least 10 years …having the ability to have very good biostatisticians… so we were able to put this thing together…

The team plotted ten years of child admissions for diarrhoea to the re-dehydration unit against daily temperatures. They found a relationship.

Dr. William Checkley, Johns Hopkins School of Public Health: El Niño trend turned the 1997 winter into a summer and this lead to an unusually high number of diarrhoea cases. … The El Niño phenomenon provided us with a window into what may happen if temperatures were to rise due to global warming. We found there was a linear relationship to diarrhoea admissions and temperature such that diarrhoea admissions increased by 8% per 1 degree Celsius, so if our results are generalized elsewhere that means that hundreds of thousand of children’s lives would be affected.

But how good is the el Niño weather phenomenon as a window into the future? So if children’s lives are potentially at stake what can Lima’s health authorities do about it? The Lima study makes clear the link between rising heat and rising childhood diarrhoea but what will it tell us about how the impact of climate change can affect public health in other parts of the globe?

PART TWO

Researchers are studying other diseases to find out if changes in weather patterns such as El Niño could be the cause. The four corners region of the United States includes Arizona, Colorado, Utah and New Mexico. During El Niño this area gets more rainfall. More rainfall and more heat means more vegetation. Some scientists think this vegetation might be responsible for spreading a potentially deadly disease. Is this another example of how changes in temperature are leading to changes in the pattern of ill-health?

Antonio Garcia: My name is Antonio Garcia and I am 18 years old. What happened to me is I decided to go camping one evening with my father and brother up to a local lake where I live. I was setting up the tent that evening. Around one o’clock in the morning, I was sleeping and I felt something crawl over my shoulder. So I grabbed it and threw it against the tent and turned on the lantern, woke up, looked around the tent and it ended up being a little mice. So we chased the mice out of the tent. I got up, and went outside and decided to a least wash my hands. Went back to sleep and about two weeks later… … I stated feeling sick, started feeling like I had the flu… So I went to the clinic, and saw the doctor, and she ended up doing a series of tests on me and she ended up concluding that I had the hantavirus…

Antonio was crippled by hantavirus.

Dr. Paul Ettestad, Veterinarian – New Mexico Dept of Health: Hantavirus gets transmitted to people mainly when the mouse … excretes it both in its urine and faeces. … if someone comes into a place where that virus is on the ground and somehow due to activity aerosolizes that virus into the air where its concentrated in that area, then breathes the virus in, then typically that’s how someone becomes infected with hantavirus.

Dr. Brian Helle, Virologist - University of New Mexico: Once a person has contracted Sin Nombre Hanta virus it goes through several steps. The virus is inhaled into the lung… and replicates in the area immediately adjacent to the lung. At that point it seeds the rest of the body…. If you can sustain the person for a while … they will eventually get rid of it. They will clear the virus. The trick is to keep them alive for a few days while their immune system does that job.

Dr. Diane Goode, Physician – University of New Mexico: Antonio is a young man that enjoyed being in the outdoors… really exploring where his life was going to lead at this stage, he came in about as close to death as you can get.

Antonio: I woke up still thinking it was the day that I came into the hospital because I didn’t know what day it was. I couldn’t feel anything from right here down. All I felt was burning and tingling. They told me it’s probably the medicine they put me under; it wears off from the head down. So I was figuring all of this was going to come back. And after a week went by, it didn’t come back …they ended up doing an MRI on me to check my spring cord and everything. … They showed that I had transverse myelitis. So my spinal core had shrunk in an area from T6 to T11.

Dr. Diane Goode: In Antonio’s case … the aftermath is he had damage to his spinal cord so he’s paralysed from the waist down.

Dr. Paul Ettestad, Veterinarian – New Mexico Dept of Health: Over the years I’ve probably investigated as many hantavirus cases as anybody in the United States has, we’ve had seventy-six cases so far now in New Mexico. When we get confirmation with a positive lab test that’s when my team wants to go out to the sight of potential expose to see what we can find there. We will set traps around the house or inside the house just to demonstrate sometimes to people that there are mice inside their home that are positive for hanta virus and are causing a risk for them. I’ve had some homes where I’ve trapped where only like two percent of the mice were positive. I’ve been in other places where we’ve had mice up to sixty percent of the mice have been positive inside the home.

With more than 15 years of data on hand, the hantavirus infection rate seems to peak every five to seven years.

Deer mice increase in warmer and wetter conditions.

More vegetation equals more food. More food equals more deer mice. Intuitively then, more infections of hantavirus. But careful study has shown this not to be the case. The linkage between deer mice, the environment and humans is not so simple.

Dr. Brian Helle, Virologist - University of New Mexico: We do have the correlation between El Niño activities and increase in hantavirus activity in New Mexico, but we don’t have really a proven mechanism for how El Niño events influence hantavirus activity.

Dr. Paul Ettestad: It’s a complex ecological cycle and to be able to predict just because of climate change that the deer mouse population will go up and nothing else will happen other than there will be more human hantavirus cases, I think is a very difficult conclusion to reach and be sure of.

Some scientists even wonder if using el Niño as an analogue to anticipate public health problems due to global warming is such a good idea after all.

Dr David Rogers, Oxford University: What people who are studying el Niño effects are hoping of course is that El Niño is in sense a paradigm for climate change in general. If things get wetter and warmer with El Niño, do we see the same changes in disease as that we’ll see when the globe gets wetter and warmer, and I think that’s quite a tall order.

Surprisingly it may be an animal disease which gives the clearest evidence that climate change is going to have an impact of human health and alter the pattern and distribution of disease. Another piece of the climate change puzzle that might be affecting health can be found in an animal disease that spread from Africa to Britain. At the Baylham House rare breeds farm in eastern England, the reality of a warming climate hit home in 2007. When bluetongue was confirmed at Baylham House Farm, authorities immediately quarantined the area – the outbreak could have a devastating effect on the cattle and sheep industry of the UK.

Dr David Rogers: Bluetongue is one of a family of viral diseases that affect a number of different animals including domestic livestock – sheep, goats and cattle. It’s transmitted from one animal to another by midges...

It’s a painful and deadly disease for the animals. Bluetongue is not transmittable to humans.

Richard Stroker, Farmer: They did an analysis of the weather patterns around about that time, and I think they reckon the midges came over carrying the virus from the continent … the wind was in the right direction at that time… the time scales of the wind pattern, followed by the incubation period, it all sort of fitted in.

The spread of bluetongue is one of the clearest instances of a disease spreading because of climate change.

Climate change doesn’t always have to have a negative impact. In fact, warmer weather may even have some positive health benefits.

Dr. Robert Gilman: As climate change occurs…there maybe some benefits to global warming – people don’t like to talk about this because obviously it is not as scary. But maybe respiratory disease may go down. Now we don’t know that yet, and we hope to analyse some data on that, but that’s the other side of the coin. Very rarely does a bad event have a silver lining somewhere.

Prof William Keatinge: For the last 30 years there has been an almost linear increase in temperature. Quite steady, it’s gone up and jiggled about during that time, but on the whole its gone up on average so much every year. The most interesting thing here is that the winter mortality has in fact been declining quite sharply… to about twenty thousand a year from thirty thousand a year. That has been stopped partly by house heating but we’re getting a benefit from global warming in that winter mortality is down.

But climate change brings not only warmth but extreme heat. In the 2003 European heat wave over 70,000 people died. In Paris, health facilities were overwhelmed.

Prof William Keatinge: Severe mistakes were made in Paris just from lack of experience. The ambulances were overwhelmed by the demand and in fact people tended to have to wait hours in a hot house then get into a hot ambulance taken to a hot hospital and with no specific training or expertise in how to handle this.

The Intergovernmental Panel on Climate Change (IPCC) say overall the negative effects of climate change outweigh the positives. But how do we respond to a threat we don’t yet fully understand? Some experts argue caution should be taken when making predictions about its effect on our future health.

David Rogers: We can make predictions about a world in 50 years time that may or may not turn out to be true, but we can never test them until we’re there.

Prof. Andrew Haines, Dir. London School of Hygiene and Tropical Medicine: There are going to be uncertainties about future projections on Climate Change and the impacts of Climate Change. But what we need to do is prepare ourselves better to react to the range of problems that may occur.

David Rogers: There’s no question that climate change will cause the change in distribution of many diseases. I think the real debate is to whether or not climate change will increase the severity of the diseases or decrease them…

Prof. Andrew Haines, Dir. London School of Hygiene and Tropical Medicine: We should be improving public health systems anyway whatever the future may bring because these will improve health in the near term. So it could provide great benefits for relatively small investments of resources and indeed will ensure we can reduce some of the adverse impacts of climate change in the future.

The overwhelming evidence is that climate change will have a major impact on human health. The question for health authorities is working out what the precise impact will be and therefore how best to target our health resources care.

END