Back in May, a group called the Marmot Review Team, in conjunction with Friends of the Earth, published a paper titled The Health Impacts of Cold Homes and Fuel Poverty. An associated editorial was also published in the British Medical Journal.
The bottom-line conclusions of the Marmot paper, which focused primarily on Britain, are that living in cold housing is harmful, that the harm falls disproportionately on the economically disadvantaged, and that fairness demands that society provide more warmth to those in “fuel poverty”.
As you might expect, my feelings about this report are mixed. On the positive side, I strongly support the authors’ sense of social justice, and of course agree that living in cold housing is potentially hazardous for elderly, disabled, or otherwise physically compromised people.
I have skepticism, however, about many of the inferences drawn in the paper, which are based primarily on epidemiologic correlations, rather than proven cause-and-effect. For example, the paper notes that there is an increase in deaths over the winter months, and goes on to state: “Cold weather, and in particular cold homes, is believed to be a main factor in causing the winter increase of respiratory and circulatory diseases”. The one citation for this statement leads to another policy paper by the same group, which, by my reading, actually provides no data whatsoever to support the assertion that cold weather (rather than, say, the increased indoor contact, lower exposer to fresh air, and lower indoor humidities common in winter) cause these diseases– let alone any evidence for the “belief” that cold homes are to blame.
Indeed, I cannot picture any way that scientific conclusions on this topic could be drawn from epidemiology alone. Why? Because in the real world there is a nearly 100% correlation between living in an “underheated” house and living in general poverty, with the myriad other social and physical risks that come with it. Just for the most obvious example, people in poverty smoke more: a report from the CDC yesterday shows that in the U.S. people living in poverty have a 43% higher likelihood of smoking than the national average, and a Gallup poll from 2008 purports that the poorest Americans smoke at rates 2-3 times that of the wealthiest. Since smoking is one of the greatest known risks for cardiovascular and respiratory diseases, it seems obvious that there could be a connection. It would be theoretically possible do a study of cold-housing morbidity risk controlling for smoking, but even if done, that would just be the tip of the iceberg in terms of the health risks of poverty.
A part of the Marmot paper which I found particularly difficult to swallow was the assertion that living in a cold house is likely to cause mental health problems. For example, citing another paper, the authors assert that “Residents with bedroom temperatures at 21º C [70º F] are 50% less likely to suffer depression and anxiety than those with temperatures of 15º C [59ºF]”. They also state that “A significant proportion of children living in cold homes felt unhappy in their family – 10% as opposed to 2% of the group living in warm homes”, without really considering whether it is the cold per se causing the “unhappiness”, or some other factor causing both the unhappiness and the cold house (many possibilities come to mind.)
In general, there is considerable confusion in this paper between the concept of cold housing, inefficient-to-heat housing, and unaffordable-to-heat housing. The first is simply a measure of temperature, the second is determined by the physical house, and the last is related to the first two but also dependent on the inhabitant’s financial situation. The authors conflate these ideas when they make statements such as, “Social isolation among older people is exacerbated by living in a cold home…. costly fuel bills prevent them from going out.” It is not, obviously, the house being cold that causes the costly fuel bills– indeed, any given house, kept colder, will have lower fuel bills than the same house kept warmer. Saying that poorly-insulated housing leads to less money for going out may well be true. But to say that a cold house causes people to stay home and isolate is… uh… wouldn’t they be more likely to hang out in a warm pub, then?
The cited paper describing the bizarre depressogenic bedroom-temperature situation also made some much wiser points. For example, the authors state that, beyond the idea of cold literally causing depression, “Fuel poverty was even more significant. Compared with householders who paid fuel bills easily, those with great difficulty paying were over four times more likely to suffer anxiety or depression”. This idea is much easier to accept than the concept of low temperatures inducing depression. They even have this nice chart, which I hope they don’t object to my reprinting:Indeed, if you combine the “cold bedroom” effect and the “stressful bills” effect, you could come to this conclusion: If, by lowering his house temperature from 71F to 59F, a person also succeeds in reducing his fuel-bill from “very difficult” to “very easy”, he will increase his risk for depression by 2-fold in one way, but reduce it by 4-fold in another way. Thus, overall, he will reduce his risk of depression by 50%.” This is great news!
Ultimately, for the connection between happiness and heat, I’ll reiterate what I’ve hypothesized before: it’s not about how warm your house is, it’s about how much control you have over how warm your house it. I’m happy living at the temperatures I do partly because I know it’s a choice, not something I have to do out of poverty. It’s the difference between rowing to exhaustion in a college regatta and rowing to exhaustion as a galley slave. Same physical experience, different mental experience. But this is not to say that cold living, when done voluntarily, is merely recreational: the dollars saved are real, and, more importantly, the resources conserved and carbon emissions prevented are also real.
With regard to the question of physical illness, I don’t think the data is there. It can’t be studied epidemiologically, because almost everyone who can afford a lot of heat, uses a lot of heat. (I’m a notable exception– and my N of 1 says, the cold did not make me sick– but you’d need hundreds or thousands of me to make a viable study.) Lacking good data, I think it is going far out on a limb to say that keeping houses chillier is a health danger to otherwise-healthy people. In fact, I think it’s environmentally criminal to suggest to people that they have to burn more oil to protect their health.