by Gianni Pezzoli
Trichlorethylene, known as trichlorethylene, together with pesticides, herbicides and hydrocarbons could induce symptoms of parkinsonism
I read that exposure to the solvent trichlorethylene, very widespread due to industrial waste, is correlated with an increased risk of Parkinson’s disease: true?
Gianni Pezzoli, neurologist, president of the Italian Association of Parkinsonians and the Grigioni Foundation for Parkinson’s responds (GO TO THE FORUM)
Among the neurodegenerative diseases, Parkinson’s is the one about which medicine has the most knowledge, better symptomatic therapies and, probably, better treatment prospects. In recent decades it has been understood that both genetics and the environment play an important role in its development. When we talk about the environment we must also consider viruses and bacteria that in many cases live with us, in our intestines, on our mucous membranes, on the skin, everywhere on us.
Substances at risk
Among the pollutants that cause the disease or anticipate it there are many pesticides and herbicides that have long been known to cause parkinsonism. Even almost all antipsychotic drugs (with the sole exclusion of quetiapine and low-dose clozapine), central anti-nausea drugs such as metoclopramide, intestinal prokinetics such as sulpiride and similar, anti-vertigo drugs such as tiethylperazine can induce Parkinson’s symptoms, especially if used for a long time. The latest pollutants to enter this long black list of disease inducers are aliphatic hydrocarbons such as hexane (often contained in stain remover mixtures) and especially halogenated ones such as trichlorethylene, another stain remover.
The case of the American military
We began to describe some cases already at the end of the 90s and then in the year 2000, after having visited almost a thousand patients, we observed how people who had used these substances presented an earlier disease and less responsive to treatment . Studies in this field of environmental neurotoxicology are always few because they are poorly financed, require large case studies, very long observation periods and ultimately sometimes difficult political choices. Recently an important American group published very interesting results in the journal JAMA Neurology. At the Camp Lejeune military base in North Carolina (USA), leaks of trichlorethylene and similar substances occurred from dry cleaning tanks, especially in the decade from 1975 to 1985.
Double number of cases
These leaks had extensively polluted the soil and aquifers so much so that the levels of trichlorethylene in drinking water were 70 times higher than the maximum allowed. Those who frequented the base were soldiers and sailors in their twenties. Now, forty years later, people who lived at Camp Lejeune have double the number of cases of probable Parkinson’s compared to a similar military base, taken as a control group. The work is certainly significant but contains some inevitable flaws. In the United States there is no generalist national health system and only 50% of the soldiers on the base continued to be followed by military medicine. Another 50% were followed, we imagine, privately and their data is not available. We in Italy have the last public health system that is still reasonably efficient, but little is done to defend it.
A sector in which to invest
The creation of large case series, available for research, is still possible and essential to prevent many diseases. In this case, through American military medicine we can reiterate that the use of solvents such as trichlorethylene is much more dangerous than it may seem, even many decades after exposure. Investing in this sector is clearly useful for us and for future generations, in order to contain what many see as a sort of Parkinson’s epidemic in the coming decades. For many other human pathologies they would benefit from it.
October 28, 2023 (changed October 28, 2023 | 08:50)
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