Reducing melamine exposure and oxidative stress markers in melamine-exposed workers: A pragmatic intervention study

Previous studies have found that melamine tableware workers are exposed to high levels of airborne melamine, which is linked to increased urinary markers of oxidative stress and kidney injury. However, the effectiveness of engineering controls in reducing such exposures had not been evaluated. To address this, an intervention was conducted in October 2016, installing two local exhaust systems combined with airflow containment curtains and a large open-end fan in high-exposure areas. Twenty-two workers were monitored before (March-April 2016) and after the intervention (November 2016). A total of 1834 air and urine samples were collected and analyzed. After the intervention, median personal melamine concentrations dropped from 159.12 to 4.51 µg/m³ (p < 0.0001), and formaldehyde levels declined from 215.99 to 162.16 µg/m³ (p = 0.002), representing 97.2 % and 24.6 % reductions, respectively. Generalized estimating equation models revealed significant decreases in diurnal urinary melamine (β = -7.02; p = 0.043) and MDA (β = -0.47; p < 0.001), though the reduction in 8-OHdG was not statistically significant (β = -0.34; p = 0.074). These results suggest that our engineering installations are effective in reducing airborne melamine exposure and short-term oxidative stress, though further research is needed to evaluate long-term health effects.