This is scientific American's 60 second science. I'm Christopher Intalyata. Got a minute?

Parts of the planet warm and cool during El Nino and Leningia, and infectious diseases also wax and wane in step with that climate cycle.

Take malaria, shown to spike in northern Venezuela during cool L L L L'Nina conditions, or flu

pandemics, which often follow months after Leningia sets in.

Now researchers have linked another public health risk to El Nino climate cycling,

poisonous viper bites.

Their study area was Costa Rica, where health centers keep rigorous records on snake bites.

They compared nine years of those snakebite records, including some 6,500 bites to climate data over the same period.

And they found that snake bites were two to three times as prevalent in the hottest and

coldest years of the El Nino climate cycle. Sounds counterintuitive, right? You might expect

the climate extremes to have opposite effects, but the researchers say in hot dry years plant

productivity peaks, driving an increase in the number of rodents, aka snake food, and potentially increasing the number of snakes.

And snakes tend to move around more in hot dry weather, increasing chances they'll encounter and attack an unlucky farmer.

In cold wet years on the other hand, prey numbers plummet, forcing snakes to travel beyond

their usual slithering grounds to eat, again increasing chances of an unlucky meeting.

The study is in the journal Science Advances.

The researchers also found two more variables that correlate strongly with

Costa Rica's odds of being bit, poverty and destitute housing. A reminder

that when it comes to dangers from environmental disruption, it's often the least fortunate who are at the greatest risk.

Thanks for the minute. For Scientific Americans 60 Second Science, I'm Christopher

and Dahlia.