All posts by Daniel Davies

London’s air pollution problem means that for the city’s older adults exercise counts for nothing

A study has concluded that even short-term exposure to air pollution in built up areas like London’s Oxford Street can negate the beneficial health effects of exercise in older adults.

The research by Imperial College London and Duke University, and published in The Lancet, adds to the growing body of evidence showing the negative impacts of urban air pollution on cardiovascular and respiratory health, and highlights the need for stricter air quality limits and greater access to green spaces.

“It’s possible that studies such as this could support new air quality limits, it shows that we can’t really tolerate the levels of air pollution that we currently find on our busy streets,” said senior author Fan Chung, Professor of Respiratory Medicine and Head of Experimental Studies Medicine at National Heart & Lung Institute at Imperial College London.

Image courtesy of Ron Porter

For the study, funded by the British Heart Foundation, researchers recruited 119 volunteers, aged over 60, who were either healthy, had stable Chronic Obstructive Pulmonary Disease (COPD) or had stable heart disease.

The volunteers were then split into two groups. One of the groups walked for two hours in a relatively serene part of Hyde Park, while the second group walked along a busy stretch of Oxford Street – which has regularly breached air quality limits set by the World Health Organization.

Physical measurements were taken before and after the walks to show the effects of the exercise on cardiovascular health, including measurements of lung volume exhaled, blood pressure and the degree to which the blood vessels could expand.

Environmental measurements were also collected, to track pollution levels and volunteers’ exposure.

Image courtesy of David Holt

Analysis revealed that all participants benefitted from a stroll in the park, with lung capacity improving within the first hour and a significant lasting increase for more than 24 hours in many cases.

By comparison, a walk along Oxford Street led to only a small increase in lung capacity in participants, far lower than recorded in the park.

Blood flow also increased after exercise, with decreases in blood pressure and an increase in heart rate. Arteries became less stiff in those walking in Hyde Park with a maximum change from baseline of more than 24% in healthy and COPD volunteers, and more than 19% in heart disease patients.

This effect was drastically reduced when walking along Oxford Street, however, with a maximum change in arterial stiffness of just 4.6% for healthy volunteers, 16% for those with COPD and 8.6% for heart disease.

“These findings are important as for many people, such as the elderly or those with chronic disease, very often the only exercise they can do is to walk,” said Chung.

“Our research suggests that we might advise older adults to walk in green spaces, away from built-up areas and pollution from traffic.”

Biologists discover earthworms are able to reproduce in Mars-like soil

If we’re going to keep ourselves alive on Mars then we need to create a sustainable agricultural ecosystem, and the news that earthworms have managed to reproduce in a Mars soil simulant could be an important step towards that.

During the Food for Mars and Moon experiment at Wageningen University & Research, which was looking at how to stimulate growth in Mars-like soil, the biologists added adult worms and pig slurry (in place on human excrement) to a Mars soil simulant provided by NASA.

But, unexpectedly, as well as allowing the biologists to grow over a dozen crops, the experiment also produced two young worms.

“Clearly the manure stimulated growth, especially in the Mars soil simulant, and we saw that the worms were active. However, the best surprise came at the end of the experiment when we found two young worms in the Mars soil simulant,” said Wieger Wamelink of Wageningen University & Research.

Images courtesy of Wieger Wamelink, Wageningen Environmental Research

Worms are very important for a healthy soil, not only on Earth but also in future indoor gardens on Mars or the moon.

They thrive on dead organic matter such as old plant remains, which they eat, chew and mix with soil before they excrete it. This poo still contains organic matter that is broken down further by bacteria, thus releasing nutrients such as nitrogen, phosphorous and potassium for use by the plants.

By digging burrows the worms also aerate and improve the structure of the soil, making watering the plants more effective. The latter proved to be very important in earlier experiments where water would not easily penetrate the soil. Wamelink confirmed that, “The application of worms will solve this problem.”

The soil stimulants, delivered by NASA, originate from a volcano in Hawaii, which simulates Mars, and a desert in Arizona, which simulates the Moon.

Since staring the experiments in 2013, the biologists has had success in growing crops such as green beans, peas, radish, tomato, potato, rucola, carrot and garden cress, which have all been tested to make sure they are safe for human consumption.

The biologists organised a dinner based on the harvested crops for the people that supported their research via a crowdfunding campaign.