Pollution by cereal waste burning in Spain

In this paper, the amount of cereal waste burned in Spain, which represents the most important source of biomass burning in this country, is estimated. During the period between 1980 and 1998, an average mass of 8 Tg of cereal waste was burned annually, with remaining 1 Tg of ash on the cereal fields after combustion. By using emission factors previously calculated by Ortiz de Zárate et al. [Ortiz de Zárate, I., Ezcurra, A., Lacaux, J.P., Van Dihn, P., 2000. Emission factor estimates of cereal waste burning in Spain. Atmos. Environ. 34, 3183–3193.], it is deduced that pollutant emissions linked to cereal waste-burning process reach values of 11 Tg CO2, 80 Gg of TPM and 23 Gg of NOx year−1 during the cereal-burning period. These emissions represent 46% of total CO2 and 23% NOx emitted in Spain during the burning period that lasts 1 month after harvesting. Therefore, the relative importance of cereal waste burning as pollutant source in Spain almost during fire period becomes evident. y, our study allows to deduce that the production of 1 kg of cereal crop implies that 410 g of carbon and 3.3 g of nitrogen are going to be introduced into the atmosphere by this pollutant process. We estimate a total gaseous emission of 3.3 Tg of C and 25 Gg N as different pollutants by cereal waste burning.