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.

Sports and trauma as risk factors for Motor Neurone Disease: New Zealand case-control study.

OBJECTIVES: To assess whether sports, physical trauma and emotional trauma are associated with motor neurone disease (MND) in a New Zealand case-control study (2013-2016). METHODS: In total, 321 MND cases and 605 population controls were interviewed collecting information on lifetime histories of playing sports, physical trauma (head injury with concussion, spine injury) and emotional trauma (14 categories). ORs were estimated using logistic regression adjusting for age, sex, ethnicity, socioeconomic status, education, smoking status, alcohol consumption and mutually adjusting for all other exposures. RESULTS: Head injury with concussion ≥3 years before diagnosis was associated with MND (OR 1.51, 95% CI: 1.09-2.09), with strongest associations for two (OR 4.01, 95% CI: 1.82-8.86), and three or more (OR 2.34, 95% CI: 1.00-5.45) head injuries. Spine injury was not associated with MND (OR 0.81, 95% CI: 0.48-1.36). Compared to never playing sports, engaging in sports throughout childhood and adulthood increased MND risk (OR 1.81, 95% CI: 1.01-3.25), as was more than 12 years playing football/soccer (OR 2.35, 95% CI: 1.19-4.65). Reporting emotionally traumatic events in more than three categories was associated with MND (OR 1.88, 95% CI: 1.17-3.03), with physical childhood abuse the only specific emotional trauma associated with MND (OR 1.82, 95% CI: 1.14-2.90), particularly for those reporting longer abuse duration (OR(5-8 years) 2.26, 95% CI: 1.14-4.49; OR(>8 years) 3.01, 95% CI: 1.18-7.70). For females, having witnessed another person being killed, seriously injured or assaulted also increased MND risk (OR 2.68, 95% CI: 1.06-6.76). CONCLUSIONS: This study adds to the evidence that repeated head injury with concussion, playing sports in general, and playing football (soccer) in particular, are associated with an increased risk of MND. Emotional trauma, that is physical abuse in childhood, may also play a role.

The carcinogenicity of pesticides used in New Zealand.

AIM: To estimate the number and weight of pesticides used in New Zealand agriculture that are classified as known or suspected human carcinogens. METHODS: The yearly usage of active ingredients was extracted from the most recent (2005) report on pesticide use. For each active ingredient, the carcinogenicity classification of three regulatory agencies (New Zealand Environmental Protection Authority [EPA NZ], US Environmental Protection Agency, European Chemicals Agency) was extracted. The International Agency for Research on Cancer (IARC) Monograph Programme's classifications were also considered. Total tonnes of active ingredients were calculated according to each classification. RESULTS: None of the pesticides are classified as known human carcinogens. In total, 56 active ingredients are listed as suspected carcinogens by at least one of the four agencies, including 16 high-use ingredients, representing up to 51% of the total yearly quantity. Agency-specific estimates ranged between 4-26% (148-872 tonnes) with the EPA NZ classification yielding the lowest estimate. The suspected carcinogen weight was highest for fungicides (estimates based on the three regulatory agencies ranged between 72-540 tonnes), followed by herbicides (60-200 tonnes) and insecticides (16 tonnes). CONCLUSIONS: New Zealand's use of pesticides that are suspected carcinogens is high. Efforts to increase awareness and reduce exposure need to be considered.

Occupation and motor neuron disease: a New Zealand case-control study.

OBJECTIVES: To assess associations between occupation and motor neuron disease (MND). METHODS: We conducted a population-based case-control study with cases (n=321) recruited through the New Zealand Motor Neurone Disease Association and hospital discharge data. Controls (n=605) were recruited from the Electoral Roll. Information on personal and demographic details, lifestyle factors and a full occupational history was collected using questionnaires and interviews. Associations with ever/never employed and employment duration were estimated using logistic regression stratified by sex and adjusted for age, ethnicity, socioeconomic deprivation, education and smoking. RESULTS: Elevated risks were observed for field crop and vegetable growers (OR 2.93, 95% CI 1.10 to 7.77); fruit growers (OR 2.03, 95% CI 1.09 to 3.78); gardeners and nursery growers (OR 1.96, 95% CI 1.01 to 3.82); crop and livestock producers (OR 3.61, 95% CI 1.44 to 9.02); fishery workers, hunters and trappers (OR 5.62, 95% CI 1.27 to 24.97); builders (OR 2.90, 95% CI 1.41 to 5.96); electricians (OR 3.61, 95% CI 1.34 to 9.74); caregivers (OR 2.65, 95% CI 1.04 to 6.79); forecourt attendants (OR 8.31, 95% CI 1.79 to 38.54); plant and machine operators and assemblers (OR 1.42, 95% CI 1.01 to 2.01); telecommunications technicians (OR 4.2, 95% CI 1.20 to 14.64); and draughting technicians (OR 3.02, 95% CI 1.07 to 8.53). Industries with increased risks were agriculture (particularly horticulture and fruit growing), construction, non-residential care services, motor vehicle retailing, and sport and recreation. Positive associations between employment duration and MND were shown for the occupations fruit growers, gardeners and nursery growers, and crop and livestock producers, and for the horticulture and fruit growing industry. CONCLUSIONS: This study suggests associations between MND and occupations in agriculture and several other occupations.

Lymphoma risk and occupational exposure to pesticides: results of the Epilymph study.

OBJECTIVES: We investigated the role of occupational exposure to specific groups of agrochemicals in the aetiology of lymphoma overall, B cell lymphoma and its most prevalent subtypes. METHODS: In 1998-2003, 2348 incident lymphoma cases and 2462 controls were recruited to the EPILYMPH case-control study in six European countries. A detailed occupational history was collected in cases and controls. Job modules were applied for farm work including specific questions on type of crop, farm size, pests being treated, type and schedule of pesticide use. In each study centre, industrial hygienists and occupational experts assessed exposure to specific groups of pesticides and individual compounds with the aid of agronomists. We calculated the OR and its 95% CI associated with lymphoma and the most prevalent lymphoma subtypes with unconditional logistic regression, adjusting for age, gender, education and centre. RESULTS: Risk of lymphoma overall, and B cell lymphoma was not elevated, and risk of chronic lymphocytic leukaemia (CLL) was elevated amongst those ever exposed to inorganic (OR=1.6, 95% CI 1.0 to 2.5) and organic pesticides (OR=1.5, 95% CI 1.0 to 2.1). CLL risk was highest amongst those ever exposed to organophosphates (OR=2.7, 95% CI 1.2 to 6.0). Restricting the analysis to subjects most likely exposed, no association was observed between pesticide use and risk of B cell lymphoma. CONCLUSIONS: Our results provide limited support to the hypothesis of an increase in risk of specific lymphoma subtypes associated with exposure to pesticides.