New Delhi, May 1: Amid increasing global warming and heat-related deaths worldwide, a new study has shown that expanding urban vegetation cover by 30 per cent could save over one-third of all deaths caused due to heat, saving up to 1.16 million lives globally.

Researchers from Monash University in Australia showed that increasing vegetation levels by 10 per cent, 20 per cent, and 30 per cent would decrease the global population-weighted warm-season mean temperature by 0.08 degrees Celsius, 0.14 degrees Celsius, and 0.19 degrees Celsius, respectively.

It can also prevent 0.86, 1.02, and 1.16 million deaths, respectively.

While increasing greenness has been proposed as a heat-related death mitigation strategy, “this is the first modelling study to estimate both the cooling and modifying effects of greenness, providing a more comprehensive assessment of its benefits in mitigating heat-related mortality,” said Professor Yuming Guo from the varsity.

The findings, published in the journal The Lancet Planetary Health, are based on a 20-year modelling study of the impact of increasing greenness in more than 11,000 urban areas from 2000 to 2019.

Urban areas in Southern Asia, Eastern Europe, and Eastern Asia were found to have the greatest reduction in heat-related deaths.

“These findings indicate that preserving and expanding greenness might be potential strategies to lower temperature and mitigate the health impacts of heat exposure,” Guo said.

Heat exposure is a major public health threat and is increasing due to climate change. Between 2000-2019, heat exposure was associated with 0.5 million deaths per year, accounting for 0.91 per cent of global mortality.

According to Guo, estimates of heat-related deaths are projected to range from 2.5 per cent in North Europe to 16.7 per cent in South-East Asia during 2090-99, “under the most extreme global warming scenarios.”

Studies show that greenness has a cooling effect on temperature, via shading surfaces, deflecting radiation from the sun, and evapotranspiration (evaporation from both the ground and plants) which promotes air convection.

This, in turn, cools the ambient temperature leading to a decrease in population heat exposure, thereby reducing the heat-related mortality burden.

In addition, greenness could also modify other related factors such as mental health, social engagement, physical activity, and air pollution, the researchers said.

Sydney, April 17: A person has died and 12 others have been infected after contracting Legionnaires’ disease in an outbreak linked to central Sydney, the Department of Health in the Australian state of New South Wales said on Thursday.

There are now 12 confirmed cases of Legionnaires’ disease in people who spent time in central Sydney between March 13 and April 5, up from the six cases that had been diagnosed as of April 10, the department said.

It said that one of the confirmed cases died in the hospital. Of the 12 reported cases, 11 have been hospitalised for treatment.

NSW Health on Thursday urged anyone who spent time in central Sydney and surrounding areas in late March or early April to be aware of symptoms of Legionnaires’ disease, including fever, chills, a cough and shortness of breath.

Legionnaires’ disease is a form of pneumonia caused by infection with Legionella bacteria, which is found naturally in fresh water. NSW Health said that symptoms can develop up to 10 days after exposure, Xinhua news agency reported.

“Outbreaks sometimes occur when bacteria from environmental sources such as cooling towers atop large buildings become contaminated,” Vicky Sheppeard, director of the southeast Sydney local public health unit, said in a statement.

“NSW Health continues to work closely with the City of Sydney to identify, inspect and sample any cooling towers in the CBD potentially implicated in the outbreak. To date, over 165 cooling towers have been inspected and tested,” she said.

According to the World Health Organisation, the Legionnaires’ disease mortality rate can be as high as 80 per cent in untreated immunosuppressed patients.

Most people catch Legionnaires’ disease by inhaling the bacteria from water or soil. Older adults, smokers, and people with weakened immune systems are particularly susceptible to Legionnaires’ disease.

Although Legionnaires’ disease primarily affects the lungs, it occasionally can cause infections in wounds and in other parts of the body, including the heart.

A mild form of Legionnaires’ disease — known as Pontiac fever — can produce fever, chills, headache and muscle aches. Pontiac fever doesn’t infect your lungs, and symptoms usually clear within two to five days.

New York, April 15: People with a certain heart valve abnormality may be at an increased risk of developing severe heart rhythm disorders also known as arrhythmias, according to a study on Tuesday.

Researchers from the Karolinska Institutet in Sweden showed that the valve abnormality called Mitral annular disjunction (MAD) increases the risk of ventricular arrhythmias — a dangerous type of heart rhythm disorder that, in the worst case, can lead to cardiac arrest.

The team found that the risk of arrhythmias persists even after successful valve surgery.

MAD is often associated with a heart disease called mitral valve prolapse, which affects 2.5 per cent of the population and causes one of the heart’s valves to leak. This can lead to blood being pumped backward in the heart, causing heart failure and arrhythmias. The disease can cause symptoms such as shortness of breath and palpitations.

The study, published in the European Heart Journal, showed that people with MAD were more likely to be female and were on average eight years younger than those without MAD.

They also had more extensive mitral valve disease.

Although the surgery was successful in correcting MAD, these patients had more than three times the risk of ventricular arrhythmias during five years of follow-up compared to patients without preoperative MAD.

“Our results show that it is important to closely monitor patients with this condition, even after a successful operation,” said Bahira Shahim, Associate Professor at the Department of Medicine, Solna, Karolinska Institutet.

In the study, the researchers investigated the risk of cardiac arrhythmias in 599 patients with mitral valve prolapse who underwent heart surgery at Karolinska University Hospital between 2010 and 2022.

The study aims to further explore new hypotheses such as that MAD causes permanent changes in the heart muscle over time, and that MAD is a sign of an underlying heart muscle disease