From: Spatial analysis between particulate matter and emergency room visits for conjunctivitis and keratitis
Visit Indexa
p value
Mean
SD
Conjunctivitis
PM10 top 20% districts
0.8
0.5
< 0.01
PM10 bottom 20% districts
0.3
0.7
Keratitis
2.4
0.9
< 0.05fIn multiple regression
1.4
1.7