Climate pain ahead for folk in the 'kidney stone belt'
By Ewen Callaway If G8 members, who recently agreed to carbon reductions that some consider lax, knew about one painful potential outcome of climate change, they might have demanded deeper cuts. Kidney stones will strike up to 2.25 million more Americans per year by 2050 because of temperature increases, research suggests. “We’re certain that climate change will continue and increase, and we’re equally certain that increased temperatures will lead to increased kidney stone formation,” says Tom Brikowski, a hydrologist at the University of Texas, Dallas. The calcium deposits, which can be excruciating to expel from the body, are caused by dehydration and low urine volume, factors likely to rise as temperatures creep up, Brikowski says. In the US, about 13% of men and 7% of women experience kidney stones during their lives, yet those rates can double in a patch of the South nicknamed the “kidney stone belt”. Kidney-stone hospitalisations tend to peak after a hot summer, and a recent US Army study also found a spike in kidney stones in soldiers, three months after they arrived in Iraq. Using the Intergovernmental Panel on Climate Change‘s latest warming models, along with regional population trends, Brikowski and colleagues worked out that that the kidney-belt zone will likely spread. California, Texas, Florida and the northeast will see the most new cases, though the South, alone, could be in for 600,000 new cases by 2050. The researchers also factored in the added costs of treating patients with kidney stones, which could balloon by a quarter, compared to today’s costs – an extra $1.3 billion a year. The team hasn’t yet crunched the numbers for the rest of the world, but Asians and Eastern Europeans, in particular, could be in for a painful future, Brikowski says. “This may be an underestimate based on what we know,” says Paul Epstein, of the Harvard Medical School. Brikowski’s projections are “based on mean annual temperature, and we know that the extremes, Iike heat waves, could play an even more severe role.” And while reducing emissions of the greenhouse gases that cause warming might slow the growth of the stone belt, drinking more water will also do, Brikowski says. “Rather than everybody parking their Hummers – although they should – you can address this directly with fluid management.” Journal reference: Proceedings of the National Academy of Sciences (DOI: 10.1073/pnas.0709652105) Climate Change – Want to know more about global warming, the science, impacts and political debate?