How is Covid -19 spread? Who is most at risk and what are the circumstances under which it is most likely to be transmitted? These questions need answers for the implementation of effective and safe strategies to end lockdown. We look at what research is showing.

And if you have to go back to work what’s the best way to protect yourself, how should we be using face coverings for example? There are lessons from research on fluid dynamics.

Also key is reducing the rate of infection, the R number, Italy relaxed lockdown a few weeks ago we look at early findings on the impact.

It’s clear more widespread and effective testing will be needed to reduce transmission, A new test which should be quicker has been developed using synthetic biology and gene editing techniques.

Also despite being a universal need, talking about our toilet use and the infrastructure that aids us remains somewhat taboo. Whilst sectors like telecommunications and computing have undergone rapid transformations over the past century, the flush toilet and wastewater system have mostly remained unchanged.

CrowdScience listeners Linda and Allison wonder if flush toilets – and the clean water used to wash waste away - make economic or environmental sense. So CrowdScience presenter Marnie Chesterton looks under the toilet lid, to probe (in a sanitary fashion) whether our sewerage systems and plumbed toilets are fit for purpose. In a future where population growth and climate change are likely to affect water demands, can we continue to use clean water to dispose of our waste and should the developing world be emulating this model?

Around 2 billion people don’t have access to proper toilets or latrines, risking serious health consequences. Marnie investigates how countries without comprehensive sewerage infrastructure deal with human waste and how science is providing novel ways to dispose of - and use – human waste. Marnie speaks to a Kenyan scientist using poo-eating fly larvae to process faeces and a North American scientist who is developing a smart-toilet she hopes will monitor our health through sampling our daily movements. Are we ready to break taboos to innovate our toilet habits?

(Image: Commuters wear masks whilst travelling on a London Underground train. Credit: Tolga Akmen/Getty Images)