Data collected by scientists from the University of Michigan has suggested that cumulative exposure to pesticides could increase the risk of developing Amyotrophic Lateral Sclerosis, otherwise known as ALS. ALS is a progressive neurodegenerative disease affecting the cells in both the brain and the spinal cord, which ultimately ends in the death of the patient.
The study, which was carried out by the team between 2011 and 2014, looked at the effects of occupational exposure, together with the effect of environmental factors, to determine how these impacted on the risk of Michigan residents developing ALS. To achieve this, the team undertook evaluations and assessments of the levels of environmental pollutants in the blood of their test subjects, together with detailed reports of exposure to such pollutants via a survey given to the participants. In total, 156 people with ALS took part in the study, with a further 128 people without ALS or any evidence of the disease in their family, being used as a control group. Of the participants, 101 ALS patients and 110 of the control group had complete demographic and pollutant data.
The team were particularly interested in the effects of organochlorine pesticides, PCBs, electrical insulation, PBDEs and brominated flame retardants, as these particular substances are known to have neurotoxic properties and a high persistence in both the body and the environment.
The results indicated exposure was associated with increased risk
According to the Michigan researchers, the results from both the survey data and the blood tests indicated that exposure to pesticides was associated with an increased risk of developing ALS. They also went on to suggest that, as the effect of environmental factors on the triggering and progression of ALS is as yet largely unknown, more studies need to be carried out in the future in order to evaluate longitudinal trends. There’s also a need for further research into some of the newer and non-persistent chemicals currently being used, plus the researchers need to learn more about the pathogenic mechanisms and undertake an assessment of phenotypic variations.
This research was published in a recent edition of the online journal JAMA Neurology.