A Temporal Association between Accumulated Petrol (Gasoline) Lead Emissions and Motor Neuron Disease in Australia

BACKGROUND The age standardised death rate from motor neuron disease (MND) has increased from 1.29 to 2.74 per 100,000, an increase of 112.4% between 1959 and 2013. It is clear that genetics could not have played a causal role in the increased rate of MND deaths over such a short time span. We postulate that environmental factors are responsible for this rate increase. We focus on lead additives in Australian petrol as a possible contributing environmental factor. METHODS The associations between historical petrol lead emissions and MND death trends in Australia between 1962 and 2013 were examined using linear regressions. RESULTS Regression results indicate best fit correlations between a 20 year lag of petrol lead emissions and age-standardised female death rate (R² = 0.86, p = 4.88 × 10(-23)), male age standardised death rate (R² = 0.86, p = 9.4 × 10(-23)) and percent all cause death attributed to MND (R² = 0.98, p = 2.6 × 10(-44)). CONCLUSION Legacy petrol lead emissions are associated with increased MND death trends in Australia. Further examination of the 20 year lag between exposure to petrol lead and the onset of MND is warranted.