Poplar, willow or eucalyptus trees, all used as fast-growing sources of renewable wood fuel for various biofuel production systems, emit high levels of the chemical isoprene as they grow, a European study contends. And the study further claims that isoprene forms toxic ozone when mixed with other air pollutants in sunlight.

The study further says that if large volumes of these trees are grown in an area, it could result in enough air pollution to reduce farmers’ crop yields, but more importantly cause nearly 1,400 “premature deaths a year in Europe by 2020,” according to a report of the study by Alister Doyle, a European correspondent for Reuters news service.

A study with such radical findings seems somewhat outrageous and hints of sponsorship by an organization or company with an agenda trying to focus biofuel production to a source other than fast growing trees. It is logical to anticipate that further studies will need to be done to confirm or disprove this initial study.

The report of the study in the journal Nature Climate Change looked at the impact of a European Union plan to slow climate change by producing more biofuels.

Doyle quoted Nick Hewitt, who worked on the study with colleagues from England's Lancaster University, in her Reuters’ article. Growing biofuels is thought to be a good thing because it can reduce the amount of carbon dioxide in the atmosphere, but Hewitt and his group went looking for any negatives.

Ozone, mainly from fossil fuels, can cause lung problems, and Doyle reports it is blamed for killing about 22,000 people a year in Europe. Overall, air pollution causes about 500,000 premature deaths in Europe a year, according to the European Environment Agency. The study says the rapidly growing forests of specific trees would add 1,400 premature deaths a year by 2020 but does not attribute a lower number of deaths from reduced ozone when other biofuels are used.

Such claims of death from air pollution are not accepted as fact by all scientists and researchers, and claims of high numbers of deaths from air pollution are not commonly suggested or accepted as fact in the U.S. 

Growing these specific trees in Europe would also reduce the annual value of wheat and maize production by $1.5 billion since ozone impairs crop growth, the study added.