OBJECTIVES Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease involving the upper and lower motor neuron of the brain and spinal cord, leading ultimately to death due to respiratory failure in most cases. The etiology of ALS is currently unknown, but several studies show that lead exposure might be one of the potential environmental causes of ALS. In this perspective, we introduce a case involving an ALS patient exposed to lead while maintaining mechanical equipment in a waste treatment plant. METHODS The patient was interviewed and his medical records were investigated to confirm the final diagnosis of ALS. The results of his health examination and working environment measurement were reviewed in order to evaluate the relation of his work with ALS. We also performed an analysis of lead concentration from samples taken from his workplace when we visited the plant to survey the work environment. RESULTS Based on the patient's clinical information, work environment, relatively high level of blood lead concentration, and several studies proposing the occupational relationship between lead and ALS, his ALS may possibly have been caused by lead exposure at his workplace. CONCLUSIONS Given the recent situation where the causal association between lead exposure and ALS is still unclear, this case report could be used as a basis to support the relevance of lead exposure with ALS, and to help improve the health and work environment of other workers who are likely to be exposed to lead.
BACKGROUND Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease involving the motor neuron of the cerebrum, brain stem, and spinal cord. It has been suggested that various occupational or environmental agents could be a cause of ALS. We report upon a case of a person contracting ALS who experienced a long-time exposure to pesticides, implying that pesticides are probable causal agents of ALS. CASE REPORTS The patient has been experiencing shoulder pain and limitation of movement that started abruptly about three years ago. Over time, these symptoms have become aggravated despite ongoing therapies including medication. After two years, he was diagnosed with ALS through electromyography, nerve conduction velocity and many laboratory tests at a university hospital in Seoul. His social and medical history was non-specific.
The patient had worked for about 15 years at a waste disposal site and mainly destroyed glass bottles containing pesticides. During this period, his respiratory tract and skin were exposed to various raw pesticides without appropriate personal protective equipment. He did this job one or two times a week and worked for two or more hours without a break.
Through an investigation into the patient's working environment, significant levels of dichlorvos, one of the organophosphates, were detected. CONCLUSIONS The study results revealed that the patient was exposed to considerable doses of pesticides as opposed to men spraying pesticides. Although controversial, pesticide exposures have been associated with ALS. However, we suggest that in this case the possibility that these pesticide exposures acted as a causal agent for the diagnosed ALS based on plausible biological mechanisms and epidemiologic data.
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Amyotrophic Lateral Sclerosis and Agricultural Environments: A Systematic Review Hyun Kang, Eun Shil Cha, Geun Joo Choi, Won Jin Lee Journal of Korean Medical Science.2014; 29(12): 1610. CrossRef
Pesticides and human chronic diseases: Evidences, mechanisms, and perspectives Sara Mostafalou, Mohammad Abdollahi Toxicology and Applied Pharmacology.2013; 268(2): 157. CrossRef