We wouldn’t drink dirty water so why do we put up with polluted air? Researchers are calling for a major rethink on our attitude to air quality. Professor Lidia Morawska, from the Queensland University of Technology, says attention to air quality during the Covid pandemic has shown how levels of airborne disease can be reduced.

Sam Wilson from the UK Medical Research Council, University of Glasgow Centre for Virus Research has been investigating genetic mechanisms associated with susceptibility to Covid infection. His team has identified a molecule that detects SARS-COV-2 when it starts to replicate in our cells. However, not all humans have this protective mechanism, which may help explain why some people become very ill with Covid and others have little if any symptoms.

Many Europeans lack this protective molecule, whereas the vast majority of Africans have it. The difference can be seen in cell cultures. However, the lack of diversity in the cells used in experiments worldwide can be a serious problem when looking at genetic differences as Samara Linton reports.

Nuclear material buried beneath the doomed Chernobyl nuclear power plant is becoming more active

And There are over 400,000 species of plant on earth, they’re on every continent including Antarctica. But humans only regularly eat about 200 species globally, with the vast majority of our nutrition coming from just three species. Many of the fruits, leaves and tubers that other plants grow are packed full of toxins that are poisonous to us, and would make us very ill if we ate them. But could we take out the poisons and create new, edible crops? That’s what CrowdScience listener Marija wants to know.

Crowdscience dives into this topic, and uncovers the that many crops are poisonous, and why so few plants are eaten globally. Host Anand Jagatia finds that even the modern scientific processes of crop breeding are very slow. But science can now engineer plants at the genetic level by adding, silencing or removing specific genes. This ‘genetic modification’ is hugely controversial but can be highly effective.

Anand finds a man who has spent decades making cotton seeds edible by removing the poisons they naturally produce in their seeds. This GM crop could help fend-off starvation. But sometimes introducing poisons can be as important as removing them, as we find in the genetically modified ‘BT eggplants’ in Bangladesh. The new gene makes the vegetable toxic to a major insect pest, so they are much easier to grow.

But GM crops are not the perfect solution. They have problems of gene escape, can increase the use of environmentally damaging herbicide, and can be open to monopolisation. In some countries, particularly in Europe, GM crops are hugely controversial. Anand finds out whether these concerns stand up to science and looks at the counterpoint in developing countries in Africa, South Asia and elsewhere, where local farmers like Patience Koku in Nigeria have little time for some of the concerns around GM, particularly as they see poor harvests, poverty and starvation as the more pressing problems.

(Photo by Sean Gallup/Getty Images)