NASA satellites track respiratory risk factors

18 May 2016

A constellation of 17 orbiting NASA satellites are shedding light on weather patterns, pollution and natural events like wildfires that can increase the risk of respiratory illness and other diseases.

Mr John Haynes, manager of NASA’s Health and Air Quality Program, said the satellites represented the world’s largest remote sensing program in non-military hands.

“Information from space can help us understand factors like climate change, the movement of airborne pollutants, and potential interactions between the environment and vector-borne disease, now very current with concern about transmission of the Zika virus by Aedes mosquitoes,” he told delegates attending the American Thoracic Society’s annual scientific meeting in San Francisco.

NASA’s long-standing program has confirmed a reduction in pollutants over the United States, including sulphur dioxide and ozone, despite increases in population, motor vehicles and energy consumption.

Also speaking at the session NASA’s satellites and models to study the environment and diseases Dr Bonnie Ford, from Colorado State University, works with epidemiologists and climate scientists at Colorado State University to integrate data from NASA satellites with surface monitors to track smoke from wildfires.

They focus on airborne particulate matter <2.5 micrometres in diameter (PM2.5), which can penetrate deep into the lung and are clearly linked with respiratory diseases including bronchitis, pneumonia and exacerbations of asthma and COPD.

“Wildfire smoke is a major source of these particles,” she said. “Exposure is likely to increase with hotter and drier conditions resulting from climate change, as well as people moving into fire-prone areas.”

Despite the health consequences there has been remarkably little research on the topic, amounting only to about 80 publications.

Dr Ford’s task is to generate accurate high-resolution data on smoke exposure to allow epidemiologists to do their work. A pilot study following a series of fires in Washington state estimated that they increased admissions for all respiratory diseases by 27%, including a 68% rise in asthma exacerbations and a 52% increase in COPD exacerbations.

Dr Ali Omar, from NASA’s oldest facility in Langley, Virginia, specialises in analysing the movement of dust around the world.

Dust particles have rough services which can harbour micro-organisms and protect them from the sterilising effects of ultraviolet light, in contrast to most other atmospheric particles – including smoke particles – which are spherical.

“Dust storms have been associated with the long-distance spread of avian influenza, coccidiomycosis, aspergillosis and Pseudomonas aeruginosa, as well as their devastating local effects,” Dr Omar said.

There are three main sources: the deserts of central Asia generate dust storms which can reach the US west coast, while storms from the Sahara can reach the US east coast. Australian deserts are the third main source. The continent’s isolation means they rarely affect other countries, although the local effects can be severe.

Dust storms are also an important beneficial influence on world ecology, for example by supplying iron and phosphorus to marine phytoplankton. The 23 million tons of Saharan dust deposited in the Amazon basin every year include about 22,000 tons of phosphorus, an essential fertiliser.

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