The most common symptoms of pneumoconiosis are cough and shortness of breath. The risk is generally higher when people have been exposed to mineral dusts in high concentrations and/or for long periods of time. Inadequate or inconsistent use of personal protective equipment (PPE) such as respirators (specially fitted protective masks) is another risk factor since preventing dusts from being inhaled will also prevent pneumoconiosis. Pneumoconiosis does not generally occur from environmental (non-workplace) exposures since dust levels in the environment are much lower.