GM plants can cut cancer-causing pollutants from home

Geneva, May 17: Spraying disinfectant on the streets, as practised in some countries, does not eliminate the new coronavirus and even poses a health risk, the World Health Organization (WHO) warned on Saturday.

In a document on cleaning and disinfecting surfaces as part of the response to the virus, the WHO says spraying can be ineffective. "Spraying or fumigation of outdoor spaces, such as streets or marketplaces, is... not recommended to kill the Covid-19 virus or other pathogens because disinfectant is inactivated by dirt and debris," explains the WHO.

"Even in the absence of organic matter, chemical spraying is unlikely to adequately cover all surfaces for the duration of the required contact time needed to inactivate pathogens." The WHO said that streets and pavements are not considered as "reservoirs of infection" of Covid-19, adding that spraying disinfectants, even outside, can be "dangerous for human health".

The document also stresses that spraying individuals with disinfectants is "not recommended under any circumstances".

"This could be physically and psychologically harmful and would not reduce an infected person's ability to spread the virus through droplets or contact," said the document.

Spraying chlorine or other toxic chemicals on people can cause eye and skin irritation, bronchospasm and gastrointestinal effects, it adds.

The organisation is also warning against the systematic spraying and fumigating of disinfectants on to surfaces in indoor spaces, citing a study that has shown it to be ineffective outside direct spraying areas.

"If disinfectants are to be applied, this should be done with a cloth or wipe that has been soaked in disinfectant," it says.

The SARS-CoV-2 virus, the cause of the pandemic that has killed more than 300,000 people worldwide since its appearance in late December in China, can attach itself to surfaces and objects.

However, no precise information is currently available for the period during which the viruses remain infectious on the various surfaces.

Studies have shown that the virus can stay on several types of surfaces for several days. However, these maximum durations are only theoretical because they are recorded under laboratory conditions and should be "interpreted with caution" in the real-world environment.

While coughing, fever and difficulty in breathing are common symptoms of COVID-19, a new case study has found that pink eye is also a reason to be tested for the disease.

The study, published in the Canadian Journal of Ophthalmology, determined that conjunctivitis and keratoconjunctivitis can also be primary symptoms of COVID-19.

The researchers noted that in March, a 29-year-old woman arrived at the Royal Alexandra Hospital's Eye Institute of Alberta with a severe case of conjunctivitis and minimal respiratory symptoms.

After the patient had undergone several days of treatment with little improvement -- and after it had been determined that the woman had recently returned home from Asia -- a resident ordered a COVID-19 test.

The test came back positive, according to the researchers.

"What is interesting in this case, and perhaps very different to how it had been recognised at that specific time, was that the main presentation of the illness was not a respiratory symptom. It was the eye," said Carlos Solarte, an assistant professor at the University of Alberta in Canada.

"There was no fever and no cough, so we weren't led to suspect COVID-19 at the beginning. We didn't know it could present primarily with the eye and not with the lungs," Solarte said.

Academic studies at the outset of the pandemic identified conjunctivitis as a secondary symptoms in about 10 to 15 per cent of COVID-19 cases, he said.

Since then, scientists have gained greater knowledge of how the virus can transmit through and affect the body's mucous membrane system, of which the conjunctiva -- the clear, thin membrane that covers the front surface of the eye -- is an extension.

While the finding provides important new health information for the public, it also makes eye exams more complicated for ophthalmologists and staff, the researchers noted.

"The patient in this case eventually recovered well without any issues. But several of the residents and staff who were in close contact with the patient had to be under quarantine," said Solarte.

"Fortunately, none who were involved in her care also tested positive," he said.

Patients coming into an eye clinic with conjunctivitis and keratoconjunctivitis are now treated as potential cases of COVID-19 and extra precautions are taken by staff, according to the researchers.

Feb 26: While too much stress can be toxic to your health, a new study suggests that despite its negative side effects, it may also lead to a surprising social benefit.

The research, published in the journal Stress & Health, found that experiencing stress made people both more likely to give and receive emotional support from another person.

This was true on the day they experienced the stressor as well as the following day.

"Our findings suggest that just because we have a bad day, that doesn't mean it has to be completely unhealthy," said study researcher David Almeida from Penn State University in the US.

"If stress can actually connect us with other people, which I think is absolutely vital to the human experience, I think that's a benefit. Stress could potentially help people deal with negative situations by driving them to be with other people," Almeida added.

For the study, the researchers interviewed 1,622 participants every night for eight nights. They asked the participants about their stressors and whether they gave or received emotional support on that day.

Stressors included arguments, stressful events at work or school, and stressful events at home.

The researchers found that on average, participants were more than twice as likely to either give or receive emotional support on days they experienced a stressor.

Additionally, they were 26 per cent more likely to give or receive support the following day.

The researchers said that while this effect, on average, was found across the participants, it differed slightly between men and women.

"Women tended to engage in more giving and receiving emotional support than men," said study researcher Hye Won Chai.

"In our study, men were also more likely to engage in emotional support on days they were stressed, but to a lesser extent than women," Chai added.

The researchers said they were surprised that stress was linked to people not just receiving emotional support, but giving it, as well.

"We saw that someone experiencing a stressor today actually predicted them giving emotional support the next day," Almeida said.

"This made me think that it's actually possible that stress helps to drive you to other people and allows it to be ok to talk about problems -- your problems, my problems," Almeida added.