Not all dusts are equal. While many are benign, some are potentially lethal and the ill effects of inhaling coal and silica dust from rock may only become apparent when victims develop silicosis after years of exposure. However, Marina Pozzolini and colleagues from the University of Genova and the Polytechnic University of Marche, Italy, explain that some sponges actively engulf silica crystals into their bodies in much the same way that damaging dust particles are encased in the lungs of silicosis sufferers. Intrigued by the possibility that modern humans may have inherited the debilitating industrial disease from our ancient sponge ancestors, Pozzolini and her colleagues began investigating how Chondrosia reniformis sponges react when they incorporate minute silica crystals into their bodies.
Sure enough, when the team exposed the sponges to silica dust, they appeared to show many of the same symptoms as human silicosis sufferers, producing fibres of collagen and a protein (tumour necrosis factor) that causes inflammation in the lungs of humans. However, the sponges’ response did not appear to be counter-productive. In fact, the beneficial symbiotic bacteria that colonise the sponges flourished after the simple animals engulfed the dust and the team also realised that the sponges were able to incorporate the silica into their skeletons for strength.
‘This phenomenon seems to indicate that quartz engulfment and erosion in C. reniformis is a positive event for the physiology of this sponge’, the team says, adding that the knowledge that factors (tumour necrosis factor) that cause inflammation in human silicosis sufferers appear to have persisted over the aeons may help scientists to develop better remedies for modern-day victims of silicosis.
