Author: BBC World Service

Most of us don’t like to dwell on our toilet habits, but this week Crowdscience has gone down the drain to discover what wastewater can tell us about our health.

It’s been more than a year since scientists across the globe started to track the spread of Covid-19, with help from home test results and hospital data. Marnie Chesterton investigates the latest tool in their arsenal: sewage. Listener Kevin has heard how human waste can be monitored to check for virus levels, and wants to know if it can also be used to stop the disease in its tracks?

Although the coronavirus has been discovered in people’s poo, so far there’s little indication it’s actually being spread through the water system. But by taking regular samples from different parts of cities, authorities are now able to accurately predict a local peak weeks before the population shows signs of sickness, then take immediate measures to alert them. In Detroit we hear how environmental engineer Professor Irene Xagoraraki used this method to detect a rare strain of Herpes which doctors didn’t even know was a potential problem.

Marnie also talks to Professor Nick Thomson from the Wellcome Sanger Institute, who sequenced the genome of the bacteria that causes cholera, to understand how it has crisscrossed the globe. He discovered that the pandemic currently devastating Yemen actually originated in Asia. It’s a discovery that has changed how the WHO is thinking about this killer disease and could have important implications for vaccination programmes. But our effluent can also pose environmental problems, and Professor Andrew Johnson from the UK’s Centre for Ecology and Hydrology explains there are now as many as 300,000 chemicals that could threaten natural habitats.

While authorities try to test each one individually, he’s concerned they may have different effects when they mix in wastewater, and current monitoring systems don’t take this into account. Not only that, but some of these substances contain silver nanoparticles, which Professor Juliane Filser tells us stick around in soil for ever, threatening organisms and bacteria at the base of the food chain.

Presented by Marnie Chesterton and Produced by Marijke Peters for the BBC World Service.

[Image: Sewage outlets. Credit: Getty Images]

As Covid cases surge almost beyond belief in India, how much is to do with social distancing, and how much to do with the mutations to the original virus?

Ramanan Laxminarayan talks to Roland from Delhi about ways in which the huge second wave could and could not have been predicted and avoided. Suggestions of the latest variant to make the headlines, B1.617, have got virologists such as Ravindra Gupta working hard to identify the clinical significance of the latest combinations of mutations.

In the journal Science, Stephen Chanock of the US Cancer program reports work with colleagues in Ukraine looking at the long footprint of radiation dosing from the Chernobyl nuclear disaster, 35 years ago this week. In the first of two papers, they find a definite footprint of radiation damage accounting for the many sad cases of thyroid cancer in people alive in the region at the time. But in another study, they looked at whether any higher level of mutations could be detected in the germlines of children conceived subsequently to parents who had experienced radiation in the disaster. While the parents' own health is often affected, 35 years on, thus far their offspring show no widespread elevated levels of disease, as was commonly expected.

And in the week that the world witnessed a guilty verdict delivered in the trial for the murder of George Floyd in the US, David Curtis of the University of Utah and colleagues report in the journal PNAS a study that suggests the widespread media coverage of acts of racial violence, including deaths at the hands of police, leads to poorer mental health in Black Americans. As the BBC’s Samara Linton reports, the study involved google search data over five years up to 2017, and nearly 2.3 million survey respondents.

Image: NurPhoto/Getty Images

Presenter: Roland Pease Reporter: Samara Linton Producer: Alex Mansfield

Grief is universal. It is something almost all of us will go through at some point. And it is something that the people we love will experience when we die.

Grief can be all consuming, it can make everyday tasks like getting out of bed, feel impossible. Which makes listener Oliver from Australia wonder - what is the point? It doesn’t bring what we lost, back.

Why have we evolved to be so affected by loss? Be it the death of a loved one, the end of a relationship or the loss of a job. Does it serve any purpose? Or perhaps it is just the price we pay for being a social species with such strong connections.

Image: Families Mourn Victims of The Tamaulipas Massacre in Tuilelén, Guatemala Photo by Josue Decavele/Getty Images

Produced by Caroline Steel and presented by Marnie Chesterton for BBC World Service.

Two weeks ago several G7 leaders called for an international treaty on Pandemic Preparedness for the future. This week 175 prominent leaders called for lifting the IP on vaccine design. And former UK PM Gordon Brown called on the G7 to finance vaccines for the world in the next two months. But are there technical difficulties that limit the pace of manufacture?

Anthony McDonnell is an economist at think tank Centre for Global Development who has been looking at the problem since last year. He suggests, amongst other things, one limit is the human expertise in manufacturing these brand-new technologies, with another being a level of vaccine nationalism that is seeing a lack of exports of components involved in manufacture.

Professor Trudie Lang heads the University of Oxford’s Global Health Network, and looks at health research across the world. She says in most countries there is no lack of public health or infrastructure potential for rolling out the vaccines, if only the supply existed.

The volcano that erupted explosively on St Vincent last week has led to many thousands of people being evacuated. Dr Joan Latchman of the University of West Indies Seismic Research Centre - who has monitored Caribbean volcanos for several decades - describes from Trinidad how the layers of ash mean recovery will take a long time, even if the explosions and pyroclastic dangers subside reasonably soon. Back in The UK, Prof Jenni Barclay and colleagues are examining rocks from the early part of the eruption, before the explosive phase began, to see if there are clues in the microstructure that could provide clues to the future.

And how do our brains so quickly tell a scream of delight from a scream of horror? Or of pain? Prof Sascha Frühholz of the University of Geneva has written in the journal PLOS Biology this week about work looking at how we identify the nature of different human screams. One finding is that we perceive joy quicker than fear..

(Image: Getty Images)

Presenter: Roland Pease Producer: Alex Mansfield

Gossip often has negative connotations, but does it get a bad rap? Might it serve a useful function and should we think of gossiping as an advanced social skill rather than a personality defect? CrowdScience listener Jayogi thinks it might be useful, and has asked CrowdScience to dig into the reasons why we find it so hard to resist salacious stories.

Presenter Datshiane Navanayagam meets a scientist who views gossip as a key evolutionary adaption - as humans started to live in bigger cooperative groups, gossiping was a way of bonding and establishing acceptable group behaviour as well as cementing reputations of trustworthiness.

Datshiane heads to the local park to catch some real gossiping in action and finds out that whilst people like to gossip they don’t consider themselves gossipers.

Datshi asks a team of scientists what information we are most keen to share and glean in these interactions and if there is such a thing as ‘good’ and ‘bad’ gossip. She hears that in some group settings – like in the workplace - gossip can enhance cooperation and limit free-riders, but that it can also have a more self-serving dark side.

Datshiane finds out if our stone-age gossipy minds are fit to operate in the world of mass communication and social media – is our fixation on celebrities related to our being hard wired to gossip?

Presenter: Datshiane Navanayagam Producer: Melanie Brown

[Image: Gossiping people. Credit: Getty Images]

On Wednesday the EU’s EMA and UK’s JCVI announced a suspected correlation between vaccination and an extremely rare type of blood clot. Prof Sabine Eichinger is a co-author of a new paper suggesting a link with vaccination or the immune response to Covid vaccination and suggests the name VIPIT for the condition. One of her patients died at the end of February having presented with a rare combination of symptoms – blood clots and a low blood platelet count. Sabine tells Roland the dots they have managed to join in the story so far.

Scientists at Fermilab in the USA posted four papers and announced an exciting development in particle physics that might lift the curtain on science beyond the Standard Model. Their measurement of something known as g-2 (“gee minus two”, just fyi), by measuring with phenomenal accuracy the magnetic properties of muons flying round in circles confirms a 20-year old attempt at a similar value by colleagues at Brookhaven. At the time, it was breathtaking but suspicious. Muons, rather like heavy electrons, don’t quite behave as the Standard Model might have us believe, hinting at fields and possibly particles or forces hitherto unknown. Dr. Harry Cliffe – a member of the LHCb team who found something similarly weird two weeks ago - describes the finding and the level of excitement amongst theorists worldwide.

Superfans around the world have learned to speak fluent Klingon, a fictional language originating from Star Trek. In a quest to understand the science behind these languages often dismissed as gobbledygook, Gaia Vince has been speaking to some of the linguists responsible for creating these languages. It’s time for her to relax the tongue, loosen those jaw muscles and wrap her head around the scientific building blocks embedded in language and what languages like Klingon tell us about prehistoric forms of communication.

Meanwhile, primatologist Edward Wright of the Max Plank Institute has been hanging out with mountain gorillas in Rwanda and recording the sound of their “chest clapping”. As he describes in the journal Scientific Reports his work confirms what scientists have long suspected - that the famous gesture - often portrayed in films - is a measure of size and strength - allowing communication in the dense, tropical forests in which the animals live.

Image: Platelets, computer illustration. Credit: Sebastian Kaulitzki /Science Photo Library via Getty Images

Presenter: Roland Pease Producer: Alex Mansfield