Table 2.

Calculation of the Air Quality Health Index (AQHI) and alternate amendments

	Calculation	Scenario*
		H−2	PM2.5 = 10 μg/m3 O3 = 11 ppb NO2 = 4 ppb	PM2.5 = 25 μg/m3 O3 = 11 ppb NO2 = 4 ppb
		H−1	PM2.5 = 15 μg/m3 O3 = 9 ppb NO2 = 6 ppb	PM2.5 = 60 μg/m3 O3 = 9 ppb NO2 = 6 ppb
		H0	PM2.5 = 51 μg/m3 O3 = 10 ppb NO2 = 5 ppb	PM2.5 = 100 μg/m3 O3 = 10 ppb NO2 = 5 ppb
AQHI	$10/10.4\ast \left(100\ast \left({\mathrm{e}}^{\left(0.000871\ast {\mathrm{NO}}_{2a}\right)}-1+e^{\left(0.000537\ast {\mathrm{O}}_{3\mathrm{a}}\right)}-1+{\mathrm{e}}^{\left(0.000487\ast {\mathrm{PM}}_{{2.5}_{\mathrm{a}}}\right)}-1\right)\right)$	2		4
Trump & Hold	When the 1-h concentration of PM2.5 exceeds 60 μg/m3, the AQHI-Plus will be boosted to 7. In addition, if the following 1-h concentration exceeds 25 μg/m3, the AQHI-Plus will be reported as 7 for that hour and the next 4 h (total of 6 h).	2		7
1-h PM2.5Only	Take the ceiling values (the closest integer greater than or equal to a given value) of the 1-h PM2.5 concentration divided by 10.	6		10
AQHI with 1.4*PM2.5	$10/10.4\ast \left(100\ast \left({\mathrm{e}}^{\left(0.000871\ast {\mathrm{NO}}_{2\mathrm{a}}\right)}-1+{\mathrm{e}}^{\left(0.000537\ast {\mathrm{O}}_{3\mathrm{a}}\right)}-1+{\mathrm{e}}^{\left(1.4\ast 0.000487\ast {\mathrm{PM}}_{2.5\mathrm{a}}\right)}-1\right)\right)$	3		5
AQHI with 2*PM2.5	$10/10.4\ast \left(100\ast \left({\mathrm{e}}^{\left(0.000871\ast {\mathrm{NO}}_{2\mathrm{a}}\right)}-1+{\mathrm{e}}^{\left(0.000537\ast {\mathrm{O}}_{3\mathrm{a}}\right)}-1+{\mathrm{e}}^{\left(2\ast 0.000487\ast {\mathrm{PM}}_{2.5\mathrm{a}}\right)}-1\right)\right)$	3		7

*AQHI/AQHI alternate amendment values for the current hour (H₀) based on pollutant concentrations in the current hour (H₀), the previous hour (H₋₁), and the hour before that (H₋₂)