Haze
In 2015, Singapore faced a significant environmental crisis when a dense, smoky haze enveloped the city-state, severely impairing visibility and air quality from September to November. This haze, primarily caused by forest fires in neighboring Indonesia, resulted in dangerously high levels of pollutants in the air, as indicated by the Pollutant Standards Index (PSI). The PSI readings during this period frequently reached levels that were classified as unhealthy, very unhealthy, or even hazardous, posing serious health risks to the population.
The Singaporean authorities and health officials strongly recommended that residents minimize outdoor activities and stay indoors as much as possible to reduce exposure to the polluted air. The situation highlighted the transboundary nature of air pollution and the need for regional cooperation in addressing environmental challenges. It also underscored the importance of emergency preparedness and public health measures in mitigating the impact of such air quality crises.