Objectively measured the impact of ambient air pollution on physical activity for older adults

BMC Public Health

Table 2 AQI, PM_2.5 and PM₁₀ categories

	Level	Alarm	Levels of health concern	Value range	N	%
AQI	1	Green	Good	0–50	517	44.68
	2	Yellow	Moderate	51–100	542	46.85
	3	Orange	Unhealthy for sensitive groups	101–150	66	5.70
	4	Red	Unhealth	151–200	32	2.77
	5	Purple	Very unhealthy	201–300	0	0
	6	Maroon	Hazardous	> 300	0	0
	1	Green	Very good^*	1–15	245	21.18
PM_2.5 (µg/m³)	2	Green	Good	15.1–25	237	20.48
	3	Yellow	Moderate	25.1–37.5	227	19.62
	4	Orange	Unhealthy for sensitive groups	37.6–50	149	12.88
	5	Red	Unhealth	50.1–75	234	20.22
	6	Purple	Very unhealthy	75.1–150	65	5.62
	1	Green	Very good^*	11–45	525	45.38
	2	Green	Good	45.1–50	0	0
PM₁₀ (µg/m³)	3	Yellow	Moderate	50.1–75	357	30.86
	4	Orange	Unhealthy for sensitive groups	75.1–100	128	11.06
	5	Red	Unhealth	100.1–150	133	11.50
	6	Purple	Very unhealthy	150.1–200	14	1.21
Temperature (°C)				-10–0	195	16.85
				0.1–10	2	0.17
				10.1–20	399	34.49
				20.1–30	542	46.85
				> 30	19	1.64
Rain	Yes				283	24.46
Rain	No				874	75.54

Notes: Levels of health concern corresponding to Health Implications, (Very) Good: Satisfactory air quality with minimal or no risk from air pollution; Moderate: Acceptable air quality, though some pollutants may pose a moderate health risk for a very few individuals highly sensitive to pollution; Unhealthy for Sensitive Groups: Health impacts may affect susceptible groups, while the general public is expected to remain unaffected; Unhealthy: Noticeable health effects for the general population, with more serious effects for sensitive groups; Very Unhealthy: Health warnings indicating urgent circumstances, with the entire population at a higher risk of being affected; Hazardous: A health alert with the potential for more serious health effects across the population
^*Very Good: WHO recommended short-term (24-hour) air quality guidelines (AQG) level before 2021; Good: After 2021

ISSN: 1471-2458