Dust levels set by EPA 

 

1.      soil clarification

Clay Mineral: Crystalline or amorphous mineral material,<2mm in diameter.

Sand: Mineral rock fragments that range in diameter from 2-0.05 mm in the USDA system

Silt: Mineral particles that range in diameter from 0.02-0.002 mm in the international system or 0.05-0.002 mm in the USDA system.

Clay Mineral: Crystalline or amorphous mineral material,<2mm in diameter.

Conversion 1 micron= 1/1,000,000 m or 1*10^-6 m or 1*10^-3 mm

Consequently 10 g/m3  is in the silt range.

2. EPA Standards.

Carbon Monoxide 9 ppm (10 mg/m3) 8-hour1 None
35 ppm
(40 mg/m3)
1-hour1 None
Lead 1.5 g/m3 Quarterly Average Same as Primary
Nitrogen Dioxide 0.053 ppm
(100 g/m3)
Annual (Arithmetic Mean) Same as Primary
Particulate Matter (PM10) 50 g/m3
Annual2 (Arith. Mean)
Same as Primary
150 ug/m3 24-hour1  
Particulate Matter (PM2.5) 15.0 g/m3
Annual3 (Arith. Mean)
Same as Primary
65 ug/m3 24-hour4  
Ozone 0.08 ppm 8-hour5 Same as Primary
0.12 ppm 1-hour6 Same as Primary
Sulfur Oxides 0.03 ppm Annual (Arith. Mean)
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0.14 ppm 24-hour1
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3-hour1 0.5 ppm
(1300 ug/m3