While this is always something to consider, generally, 6-fold increase in risk due to exposure is likely not just a population demographic artifact.
TCE and its relation to Parkinson's has been studied for at least the last 15 years. Though I haven't come across anything definitive on the mechanism of action, there seems to be indication that a combination of TCE or its analogues combined with other risk factors (assumed to be genetic) generates substantial progressive dopaminergic neuron loss, a hallmark of Parkinson's disease progression.
TCE and its relation to Parkinson's has been studied for at least the last 15 years. Though I haven't come across anything definitive on the mechanism of action, there seems to be indication that a combination of TCE or its analogues combined with other risk factors (assumed to be genetic) generates substantial progressive dopaminergic neuron loss, a hallmark of Parkinson's disease progression.