| First author [ref.] | Asthma definition | Exposure metric | Co-exposures | OR (95% CI) |
| Beard [15] | Self-reported asthma | Board of Tick Control (NSW, Australia) records used to estimate type of chemical and duration of exposure estimates | Agricultural environment, cattle | 1.59 (1.05–2.43) |
| Boers[16] | Self-reported, doctor-diagnosed asthma | Job history of exposure to pesticides (yes/no) | Agricultural environment (for some participants) | 0.41 (0.15–1.11) |
| Urinary markers | 1.18 (0.93–1.50) | |||
| Chakraborty [17] | Self-reported, doctor-diagnosed asthma | Split into regular sprayers (at least 1 h a day, 5 days per month for 5 years) or occasional sprayers | Agricultural environment | 1.34 (1.09–1.79) |
| Faria [18] | Symptoms of asthma (≥2 episodes of wheezing with shortness of breath in lifetime) | Apply pesticides >3 days per month versus no exposure | Agricultural environment, cattle, birds, horses | 2.12 (1.19–3.75) |
| Hoppin [9] | Self-reported, doctor-diagnosed, adult-onset asthma | Use of any pesticide, lifetime total years of pesticide use and frequency | Agricultural environment | 1.46 (1.14–1.87)# |
| 1.00 (0.82–1.22)¶ | ||||
| Hoppin [10] | Self-reported, doctor-diagnosed, adult-onset asthma | History of high pesticide exposure events | Agricultural environment | 1.98 (1.30–2.99)# |
| 1.96 (1.49–2.56)¶ | ||||
| Nriagu [19] | Self-reported doctor-diagnosed asthma | Use of insecticides in the home | Unknown | 3.67 (1.19–11.3) |
| Schenker [20] | Self-reported diagnosed asthma ever | Paraquat exposure using a cumulative paraquat exposure index | Agricultural environment (banana, coffee and palm oil) | 1.60 (0.9–3.0) |
| Zhang [21] | Self-reported attack of asthma in last 12 months | Self-reports of insecticide exposure | Outdoor agricultural worker, biomass fuel burning | 1.9 (1.3–2.9) |
| Huang [22] | Lung function testing and symptom reporting | Exposure measured based on job title and air monitoring | Unknown | NR |
| Jones [23] | Death from asthma or other respiratory problems | Employment in relevant industry | Unknown | Mortality study, NR. Asthma was not reported as a separate outcome |
| Yemaneberhan [24] | Self-reported asthma, wheezing or cough | Self-reported exposure questionnaire | Considered and included smoking and atopy | The results of children and adults were not reported separately |
#: atopic asthma; ¶: nonatopic asthma. NR: not reported.