The slight improvement in the air quality index provided a respite to the residents, who still grappled with a thick, hazardous haze enveloping the city.

The statement highlights the ongoing air quality issues faced by residents of a city shrouded in thick, hazardous haze, despite a slight improvement in the air quality index (AQI). This implies that while there is some progress, the situation remains serious for the inhabitants.

Factors contributing to the poor air quality could include pollution from vehicles, industrial emissions, and natural events like wildfires. The description evoked by the "thick, hazardous haze" suggests that the air quality is not just moderately poor but potentially harmful to health and daily activities.

It's important for city officials and environmental agencies to continue monitoring air quality and implement measures to improve it, such as promoting cleaner transportation options, regulating industrial emissions, and increasing green spaces in urban areas. Public awareness campaigns can also help educate residents on coping strategies during poor air quality days, such as staying indoors and using air purifiers.

Overall, the situation outlines the need for continued efforts to address air quality issues and protect public health.