Introduction:
The sugarcane harvest migrant workers are an underprivileged group in Thailand and have a high risk of exposure to secondhand smoke but are potentially neglected in health promotion interventions.

Methods:
This three-phase study applied a mixed-method research approach. The data were collected from February to December 2019 from the Sukhothai province of Thailand. In Phase 1, the level of secondhand smoke exposure of the sugarcane harvest migrant workers at the worker camp was explored. The data were collected from 462 workers by questionnaires and from 24 sample participants in the group discussions about the factors leading to the exposure to secondhand smoke. Phase 2 was the provision and implementation of social measures for the health protection of migrant workers and families from exposure to secondhand smoke. In Phase 3, an evaluation of the health protection model for the migrant workers and families from secondhand smoke exposure was explored.

Results:
Workers aged ≤40 years had 1.9 times higher exposure to secondhand smoke than workers aged ≥41 years (OR=1.93; 95% CI: 1.24–3.01). Those who worked overtime had 1.7 times higher exposure to secondhand smoke than those who did not work overtime (OR=1.71; 95% CI: 1.10–2.66). Social measures to prevent secondhand smoke were: given a warning, no rewards for cigarettes, designated smoking area, not asking the children to buy cigarettes, stop displaying cigarettes at grocery shops, and empowering woman to go against the smoking husband in the camp and the sugarcane field when the women, children, and nonsmokers are present. After implementing the measures, there was no exposure to secondhand smoke inside the room, cooking area, and at the quad in the camp center.

Conclusions:
Appropriate social measures for health protection can help to reduce exposure to secondhand smoke.