Table 3.

Odds ratios (ORs) [95% confidence intervals (CIs)] of hearing loss ($>25\mathrm{d}\mathrm{B}$) by blood lead, mercury, and cadmium levels in single-pollutant models in adults ($n=\mathrm{5,187}$).

Variablesa	Speech-frequency PTAb		High-frequency PTAc
	No. hearing loss/No. participants	ORs (95% CIs)	No. hearing loss/No. participants	ORs (95% CIs)
Lead
Per doubling of lead	1,124/5,187	1.15 (0.94, 1.41)	1,124/5,187	1.30 (1.08, 1.57)
Lead quartile (µg/dL)
$\mathrm{Q}1\left(0.327–1.593\right)$	170/1,296	1 (Reference)	276/1,296	1 (Reference)
$\mathrm{Q}2\left(1.594–2.146\right)$	204/1,296	0.94 (0.65, 1.35)	420/1,296	1.13 (0.83, 1.53)
$\mathrm{Q}3\left(2.148–2.822\right)$	330/1,298	1.29 (0.92, 1.78)	587/1,298	1.35 (1.00, 1.81)
$\mathrm{Q}4\left(2.823–26.507\right)$	420/1,297	1.25 (0.87, 1.79)	810/1,297	1.70 (1.25, 2.31)
$p-\text{Trend}$		0.066		$<0.001$
Mercury
Per doubling of mercury	1,124/5,187	0.96 (0.84, 1.08)	1,124/5,187	0.98 (0.87, 1.09)
Mercury quartile ($\mathrm{\mu }\mathrm{g}/\mathrm{L}$)
$\mathrm{Q}1\left(0.363–2.378\right)$	284/1,296	1 (Reference)	469/1,296	1 (Reference)
$\mathrm{Q}2\left(2.379–3.528\right)$	250/1,297	0.84 (0.61, 1.17)	460/1,297	0.89 (0.68, 1.16)
$\mathrm{Q}3\left(3.529–5.369\right)$	267/1,296	0.79 (0.58, 1.09)	524/1,296	0.83 (0.63, 1.08)
$\mathrm{Q}4\left(5.370–60.678\right)$	323/1,298	0.84 (0.63, 1.12)	640/1,298	0.89 (0.68, 1.17)
$p-\text{Trend}$		0.221		0.382
Cadmium
Per doubling of cadmium	1,124/5,187	1.18 (1.00, 1.39)	1,124/5,187	1.25 (1.08, 1.44)
Cadmium quartile ($\mathrm{\mu }\mathrm{g}/\mathrm{L}$)
$\mathrm{Q}1\left(0.068–0.689\right)$	140/1,293	1 (Reference)	289/1,293	1 (Reference)
$\mathrm{Q}2\left(0.690–1.033\right)$	255/1,300	1.04 (0.73, 1.49)	489/1,300	1.10 (0.81, 1.49)
$\mathrm{Q}3\left(1.035–1.470\right)$	340/1,299	1.22 (0.86, 1.72)	645/1,299	1.43 (1.06, 1.93)
$\mathrm{Q}4\left(1.471–6.422\right)$	389/1,295	1.30 (0.88, 1.91)	670/1,295	1.47 (1.05, 2.05)
$p-\text{Trend}$		0.117		0.007

Note: Models were adjusted for age, ${\text{age}}^2$, sex, education, body mass index, cigarette smoke, current diagnosis of hypertension, current diagnosis of diabetes, occupational noise, recreational noise, and firearm noise. PTA, pure tone average.

^aHearing loss was defined as pure tone average $>25\text{dB}$.

^bSpeech-frequency PTA at 0.5, 1, 2, and 4 kHz.

^cHigh-frequency PTA at 3, 4, and 6 kHz.