Navajo Coal Combustion and Respiratory Health Near Shiprock, New Mexico

Table 3

Selected results for trace metal concentrations (μg/m³) from ambient air samples collected in 2005. Zero values indicate that the element, if present, was below the detection limits.

Element	Nav1	Nav10	Nav22	Nav16	Nav50	Nav7	Nav44	Nav38	Nav11	Nav34	Nav25	Nav26	health levels
arsenic (As)	0.005	0.012	0.014	0.021	0.028	0.001	0.004	0.040	0.001	0.005	0.007	0.006	10^a
beryllium (Be)	0	0	0	0	0	0	0	0	0	0	0	0	0.01^b
chromium (Cr)	0.003	0.013	0.014	0.001	0	0.007	0	0.014	0	0.007	0	0	500^c
cadmium (Cd)	0	0	0	0	0	0	0	0	0	0	0	0	100^a
lead (Pb)	0	0.002	0.003	0.005	0.004	0.002	0.002	0.007	0.001	0.001	0.002	0.003	1.5^d
manganese (Mn)	0.001	0.008	0.005	0.007	0.007	0.003	0.002	0.026	0.003	0.005	0.007	0.014	5000^a
mercury (Hg)	0	0	0	0.001	0	0	0	0.001	0	0.001	0.002	0.001	100^a
nickel (Ni)	0	0.003	0	0	0	0.008	0.001	0.018	0	0.001	0.003	0	1000^a
selenium (Se)	0.001	0.007	0.010	0.007	0.009	0.004	0.003	0.041	0.002	0.004	0.004	0.008	200^a
antimony (Sb)	0	0.001	0.001	0.001	0.002	0.001	0.002	0.001	0	0	0.002	0.002	500^a
cobalt (Co)	0	0	0	0	0	0	0	0	0	0	0	0	100^a

(a) Agency for Toxic Substances and Disease Registry—8 hour work day, 40 hour work week (http://www.atsdr.cdc.gov/tfacts4.html).
(b) Agency for Toxic Substances and Disease Registry—30 day period (http://www.atsdr.cdc.gov/tfacts4.html).
(c) National Institute for Occupational Safety and Health—time-weighted average (10 hours)
(http://www.atsdr.cdc.gov/HEC/CSEM/chromium/standards_regulations.html).
(d) U.S. EPA, NAAQS—quarterly average (http://www.epa.gov/air/criteria.html).