MELBOURNE, Australia --- Researchers at Deakin University have concluded that diesel exhaust is far more damaging to human health than exhaust from biodiesel. Associate Professor Leigh Ackland, associate head of Deakin's School of Life and Environmental Sciences, led a team of researchers who compared the effects of diesel exhaust and biodiesel exhaust on human airway cells. They found that diesel exhaust damaged and killed the cells, while biodiesel exhaust had little effect. "Australia's escalating need for fuel is posing a major health problem," Associate Professor Ackland said. "The fumes from burning fuels, including diesel, contribute to pollution and can cause heart disease, bronchitis and asthma. Efforts are underway to replace petrol and diesel with cleaner biofuels, such as biodiesel, but there is considerable resistance to this. This study provides clear evidence that diesel exhaust is more harmful to our health than biodiesel exhaust." Since it's not possible to study in real time what happens in the real human airway, the researchers conducted their research on human airway cells grown in a culture. The cells were exposed to the particulate matter emitted in diesel and biodiesel exhaust fumes. "Particulate matter is the burnt material, including carbon particles, emitted into the air," Ackland explained. "This particulate matter is part of biodiesel and diesel fumes, but the particles produced from biodiesel were much less damaging to the cells than particles produced from diesel. Our research found that the particulate matter from diesel exhaust stimulated a 'death pathway' response that the body uses to dispose of damaged cells. This response caused the airway cells to fuse together and die. We saw hardly any cell death after treatment with biodiesel particulates." Given the level of cell death the researchers found, they concluded that diesel exhaust could cause respiratory disorders such as asthma and could even be implicated in cancer, Ackland said. The study has been published in the lastest edition of the international journal Immunology and Cell Biology.