Environmental exposure to pesticides and Amyotrophic Lateral Sclerosis in the South of Spain

Croplands proximity is associated with amyotrophic lateral sclerosis incidence and age at onset

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease resulting from an intricate interplay between genetics and environmental factors. Many studies have explored living in rural areas as a possible risk factor for ALS, without focusing simultaneously on incidence, age at onset and phenotypic features.

OBJECTIVE

To evaluate the effect of croplands residential proximity on ALS incidence and phenotype, focusing on age of onset, site of onset and progression rate.

METHODS

The address history of ALS patients belonging to the population-based Piemonte and Valle d'Aosta registry (PARALS), diagnosed between 2007 and 2014, was obtained for the 20 years prior to the onset date. The smoothed ALS incidence per year (im) was compared with the percentage of area covered by each crop for each municipality. A proximity score was calculated for each cropland by geolocation, measuring the percentage of area surrounding patients' residence for variable radii, and was used to compare croplands exposure and phenotype.

RESULTS

We observed an increased ALS incidence in the municipalities with a higher percentage of area covered by arable crops (R = 0.191, p < 0.001). Age at onset was significantly lower in those patients who lived near arable crops, with a median anticipation ranging from 1.8 to 3.4 years; using historical data, a significant anticipation was found also for patients living near vineyards.

DISCUSSION

Our study proved a direct association between arable crops and ALS risk and an inverse association between arable crops and vineyards proximity and age at onset, suggesting the possible causative role of specific environmental contaminants.

Temporo-spatial analysis of amyotrophic lateral sclerosis in Spain: Altitude and land use as new determinants of the disease

INTRODUCTION

Amyotrophic lateral sclerosis (ALS) is the most common neurodegenerative disease affecting motor neurons. Currently, ALS is conceived as the result of the interaction between genetics, environmental factors, and aging. This study analyzed the spatial and temporal patterns of ALS in Spain, delving into the potential relationships between altitude, land cover, and this disease.

METHODOLOGY

ALS death data were collected over a 19-year period, including information on sex, age and municipality of residence. The standardized mortality rate was calculated for each municipality of residencia, and Anselin's local Moran's I statistic was used to identify clusters of high and low incidence. Altitude data were sourced from the Copernicus Land Monitoring Services, while land cover data came from CORINE satellite images and national agricultural statistics.

RESULTS

The average annual incidence of ALS deaths among adults was 2.5 per 100,000 people. Higher mortality rates were noted in males (2.8) than in females (2.3), with both sexes exhibiting a rising mortality trend in a temporal analysis. Cluster analysis revealed that high mortality areas were mostly located in the North and Northeast of the country. Municipalities in these clusters had significantly lower median altitudes and larger areas of Permanently Irrigated Arable Land and Broad-Leaved Forest.

CONCLUSION

This study provides new evidence about the increase in ALS cases in European countries during the last decades, reporting for the first time altitude and certain agricultural land uses as potential geographic determinants of the disease.

Clinical and Sociodemographic Factors Related to Amyotrophic Lateral Sclerosis in Spain: A Pilot Study

Background: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease of unknow etiology. Male sex is a well stablished risk factor, but other factors such as early and adult life expositions show contradictory evidence. Aim: to explore the link of clinical, sociodemographic, and occupational factors with ALS patients in Spain and the impact of these factors in functionality. Methods: A cross-sectional study was conducted with ALS patients and healthy controls. Registered variables were smoking, arterial hypertension, diabetes mellitus type 2, previous cancer to reproductive organs or breast, occupational exposure, and early life exposures. Functionality in ALS patients was compared according to each exposure. Results: The ALS group consisted of 59 participants and the control group of 90 participants. ALS patients showed a significant association with previous cancer (p = 0.011), occupational exposure (p < 0.001), and older siblings (p = 0.029). ALS patients presented significant differences in BMI according to hypertension and older-sibling factors. Moreover, respiratory function was affected in patients with previous cancer (p = 0.031). Conclusions: Occupational exposure and previous cancer to reproductive organs or breast could be linked to ALS patients. In addition, hypertension and previous cancer could affect their BMI and respiratory function. Other factors such as longer smoking periods and exposition to older siblings could also characterize ALS patients.

Occupational exposures to pesticides and other chemicals: a New Zealand motor neuron disease case–control study

Objectives

To assess associations between occupational exposures to pesticides and other chemicals and motor neuron disease (MND).

Methods

A population-based case–control study that included 319 MND cases (64% male/36% female) recruited through the New Zealand MND Association complemented with hospital discharge data, and 604 controls identified from the Electoral Roll. For each job held, a questionnaire collected information on 11 exposure categories (dust, fibres, tobacco smoke, fumes, gas, fumigants, oils/solvents, acids/alkalis, pesticides, other chemicals and animals/animal products). ORs were estimated using logistic regression adjusting for age, sex, ethnicity, socioeconomic status, education, smoking, alcohol consumption, physical activities, head/spine injury and other occupational exposures.

Results

Two exposure categories were associated with increased MND risks: pesticides (OR 1.70, 95% CI 1.17 to 2.48) and fumigants (OR 3.98, 95% CI 1.81 to 8.76), with risks increasing with longer exposure duration (p<0.01). Associations were also observed for: methyl bromide (OR 5.28, 95% CI 1.63 to 17.15), organochlorine insecticides (OR 3.28, 95% CI 1.18 to 9.07), organophosphate insecticides (OR 3.11, 95% CI 1.40 to 6.94), pyrethroid insecticides (OR 6.38, 95% CI 1.13 to 35.96), inorganic (copper) fungicides (OR 4.66, 95% CI 1.53 to 14.19), petrol/diesel fuel (OR 2.24, 95% CI 1.27 to 3.93) and unspecified solvents (OR 1.91, 95% CI 1.22 to 2.99). In women, exposure to textile fibres (OR 2.49, 95% CI 1.13 to 5.50), disinfectants (OR 9.66, 95% CI 1.29 to 72.44) and cleaning products (OR 3.53, 95% CI 1.64 to 7.59) were also associated with MND; this was not observed in men (OR 0.80, 95% CI 0.44 to 1.48; OR 0.72, 95% CI 0.29 to 1.84; OR 0.57, 95% CI 0.21 to 1.56, respectively).

Conclusions

This study adds to the evidence that pesticides, especially insecticides, fungicides, and fumigants, are risk factors for MND.