Hong Kong’s Indoor Air Quality Worse Than Outdoors, Recent Study Finds

Hong Kong is grappling with a significant environmental challenge—indoor air pollution.

According to Dyson's first-ever Global Air Quality Connected Data project, Hong Kong experienced worse indoor air quality than outdoor for a staggering 8 months in 2022, with January being the most polluted month.

The study analysed data collected by more than 2.5 million connected Dyson air purifiers, providing valuable insights into the real pollution levels in homes across the world. Among the key observations, 60% of cities globally saw higher annual average indoor PM2.5 levels compared to outdoor levels. Hong Kong recorded an indoor PM2.5 level 8% higher than outdoor, with every month of the year surpassing the World Health Organization's (WHO) long-term exposure guidance.

The study also highlighted that winter, in general, was the most polluted season across all regions. In Hong Kong, January emerged as the most polluted month, with an indoor PM2.5 level exceeding the WHO guideline by more than 5 times. The most polluted time of day, on average, fell between 6 PM and midnight, coinciding with when people are typically most active in their homes.

Indoor air pollution is a significant health concern, as it can lead to various respiratory issues and chronic diseases. Dyson's data underscores the urgent need for awareness and action to address this critical problem. The study's findings serve as a powerful education tool, by understanding the pollution patterns on a daily, monthly, and seasonal basis, individuals can take steps to reduce their exposure and improve their air quality.

Hong Kong's struggle with indoor air pollution underscores the broader global challenge. With cities like Delhi, Beijing, and Shanghai also ranking among the top 10 cities with high indoor PM2.5 levels, concerted efforts are necessary to combat this issue effectively.