People Fixing the World

It's estimated that a person dies from a snakebite every five minutes. Many more people face life-changing injuries, losing limbs and consequently their livelihoods. Antivenoms are expensive to make and are in short supply, particularly in remote communities where they are needed the most. And what’s more, snakebites in different parts of the world need different types of antivenoms. Many of the current treatments available in sub-Saharan Africa have been developed from snakes in Asia, but antivenom made to treat Indian snakebites won’t work as well on people bitten by snakes in Africa. Now a new research facility in Kenya is trying to develop better antivenoms from African snakes. And they've launched a motorbike snakebite ambulance service too, to get people who have been bitten to hospital fast. (Photo Credit: BBC)

For the past 20 years, police chiefs and policy makers around the world have been fascinated by an idea: that violence spreads through cities like a disease, with patterns of clustering and transmission, and opportunities to inoculate communities against it. Violence-reduction programmes, influenced by epidemiology, have been implemented in Chicago, Glasgow and - most recently - London. But before these initiatives, a link between violence and disease was made by a Colombian doctor called Rodrigo Guerrero. When Guerrero became mayor of Cali in Colombia in 1992, the city was in crisis. It was the height of a war between the Cali and Medellin drug cartels with the homicide rate reaching a shocking 120 per 100,000 people. Guerrero’s approach was not to wage a war against the cartels, or to cave into corruption. Instead, he used his knowledge as a Harvard-trained epidemiologist to gather data about the exact causes of homicide, make hypotheses, and try interventions. “I was no longer an epidemiologist, but a violentologist,” he recalls. In this programme Dr Guerrero gives reporter William Kremer a tour of his city and explains his approach. Reporter: William Kremer (Photo Caption: Dr Rodrigo Guerrero / Photo Credit: BBC)

In the 1970s hundreds of thousands of wells were dug across Bangladesh to give people access to cholera-free water. But this led to what the World Health Organization has called the largest mass poisoning of a population in history, worse than Chernobyl. That’s because the water in the wells wasn’t tested for arsenic. Decades on, it’s a major problem. The WHO says more than 35 million Bangladeshis have been chronically exposed to arsenic in their drinking water, and about 40,000 die of arsenicosis every year. The field test for it is inaccurate and prone to human error. Most Bangladeshis drink from wells in their back yards which haven’t been tested for years, if at all. But now a gadget is being developed which will allow anyone to test a well cheaply, instantly and accurately. The scientific key to it is a tiny enzyme, found inside a bacterium affectionately known as Mr Tickle, which was discovered in an Australian gold mine. Reporters: Chhavi Sachdev and Jo Mathys (Photo Credit: BBC)

Pollution, overfishing and oxygen depletion are damaging coastal waters across the world. Often fish and other marine life are the victims, but scientists are using one surprising creature to help solve the problem – the oyster. Oysters eat some chemical pollutants and fight algae blooms, which can have a damaging effect on biodiversity. A group of teachers and scientists in New York is trying to reintroduce a billion of them into the harbour to make it a healthier, cleaner environment and strengthen the shoreline. Another team based in France is strapping wires to oysters’ shells around oil rigs to monitor how often they open and close. That gives them vital information about how pollution levels are changing. Reporter/ producer Jamie Ryan (Photo Credit: Getty Images)

Concrete is the most used man-made product in the world but it comes with a heavy environmental price. Between 5% and 7% of the world's annual carbon emissions come from producing the cement that glues concrete together. Most of these climate-changing gases are released when a vital ingredient, limestone, is melted down in the manufacturing process. But one company has devised a new type of cement that only solidifies when you pump carbon dioxide into it. The gas becomes locked in as it turns to concrete. This is similar to the way carbon dioxide has been stored in rocks by nature over millions of years. As Nick Holland reports, it's one of the solutions the industry could use to mitigate its impact on the environment. (Photo Credit: BBC)