▁National ▁Amb ient ▁Air ▁Qu ality ▁Standard ▁for ▁daily ▁expos ure ▁to ▁particul ates ▁in ▁the ▁ 2 . 5 ▁mic rom eters ▁and ▁smaller ▁category ▁from ▁ 1 5 μ g / m 3 ▁to ▁ 1 2 μ g / m 3 ▁in ▁ 2 0 1 2 . ▁As ▁a ▁result , ▁U . S . ▁annual ▁PM 2 . 5 ▁aver ages ▁have ▁decre ased ▁from ▁ 1 3 . 5   µ g / m 3 ▁to ▁ 8 . 0 2   µ g / m 3 , ▁between ▁ 2 0 0 0 ▁and ▁ 2 0 1 7 . ▁ ▁References ▁ ▁External ▁links ▁ ▁Category : P oll ution ▁Category : At mos pher ic ▁sciences ▁Category : Environment al ▁chem istry ▁Category : Environment al ▁science <0x0A> </s> ▁All is ▁is ▁a ▁surname . ▁Notable ▁people ▁with ▁the ▁surname ▁include : ▁ ▁Edward ▁P . ▁All is , ▁founder ▁of ▁what ▁was ▁to ▁become ▁All is - Ch al mers , ▁and ▁prominent ▁in ▁the ▁Green back ▁Mov ement ▁Charles ▁David ▁All is ▁( born ▁ 1 9 5 1 ), ▁American ▁bi ologist ▁John ▁All is ▁( born ▁ 1 9 4 2 ), ▁American ▁cycl ist ▁Louis ▁All is ▁( 1 9 1 6 – 1 9 9 4 ), ▁American ▁industrial ist ▁and ▁Wisconsin ▁Secretary ▁of ▁State ▁O sw ald ▁T . ▁All is ▁( 1 8 8 0 – 1 9 7 3 ), ▁American ▁the olog ian ▁Thomas