Scientists Discover Wood Burning Stoves Cause Alarming Risk to Environment

wood burning stove

A recent study from the University of Surrey has shown that emissions in major cities caused by restaurants like pizzerias and steakhouses that use wood burners can be very harmful to the urban environment. The complete findings were published in Atmospheric Environment journal and point to the underlining causes of pollution of the Latin American city of São Paulo in Brazil.

The work is an in-depth collaboration between the world’s leading air pollution experts from seven different Universities, lead by the University of Surrey’s Dr. Prashant Kumar from the Department of Civil and Environmental Engineering, under the umbrella of University Global Partnership Network (also known as UGPN).

São Paulo is the only megacity in the world that uses a far cleaner bio-fuel driven fleet. The city holds about 10% of Brazil’s total population, São Paulo’s inhabitants use biofuel in their vehicles made up of sugarcane ethanol, gasohol (which is 75% gasoline and 25% ethanol) and soya diesel.

Dr Kumar says it became very evident from their work that while there is not the same high level of pollutants from vehicles in the city of São Paulo, there had not previously been much consideration of some of the unaccounted for sources of emissions. These include wood burning in thousands of pizza shops and also the burning of domestic waste.

Feijoada, a bean and pork stew, is often known as Brazil’s national dish but pizza is loved by the residents of the city. Pizza Day is celebrated every July and the neighborhood pizzeria is the Sunday dinner with the family venue for most of the residents within the city. People young and old line up for hours outside pizzerias on Sunday nights. São Paulo contains about 8,000 pizza parlors that make about one million pizzas each and every day and can hold around 600 people at a time. There are about 800 pizzas being made using the old-fashioned wood burning stoves and about 1,000 each day are made for home deliveries.

Dr. Kumar explains that there are about 7.5 hectares of Eucalyptus forest being burned each month by pizzerias and steakhouses alone. This amounts to a total of 307,000 tons of wood being burned every year. This is a large amount of waste, enough to cause a significant threat to be a real concern to the environmental negating the positive effect on the environment that compulsory green biofuel policy has on vehicles.

Co-author of the study, Professor Maria de Fatima from the University of São Paulo states that while there is a large number of passenger vehicles and diesel trucks that are the dominant contributors to particle emissions, it is important that we understand other ways that the environment is being harmed. These numbers need to be accounted for so they can be used in future studies because they are significant contributors as pollutants.

Professor Yang Zhang from the North Carolina State University, another co-author says that once in the air, the emitted pollutants can undergo complex physical and chemical processes to form harmful secondary pollutants such as ozone and secondary aerosol. Most studies thus far have focused on the impacts of vehicles and their emissions on both air quality and human health, the impacts of emissions from wood and coal burning and meat-cooking in pizzerias and restaurants has not yet been completely quantified.

Another large part of the problem is the impact of the Amazon rainforest. Biomass burning from the south southern edge of the forest can be transported across the Atlantic coast to Brazil and has to be included in the qualitative assessments of the city air pollution. Dr. Kumar cites his most recent work by saying that the team involved in the project believe that the contents of this new direction article provide an unprecedented approach that helps to examine the adverse impact of air pollution in a unique megacity like São Paulo.

Vince Emery, Professor and Senior Vice President of the Global Strategy and Engagement says this is another exciting example of how global challenges such as air pollution in cities need global networks to identify the problems and ultimately create innovative solutions.