Table 5.

OR for hearing loss by joint effect between blood lead and cadmium levels with the low-frequency method

Variable	Low lead	High lead	Lead within strata of cadmium
Low cadmium	Ref.	1.26 (0.76–2.11)	1.26 (0.76–2.11)
High cadmium	1.28 (0.74–2.20)	1.13 (0.66–1.93)	0.86 (0.57–1.31)
Cadmium within strata of lead	1.28 (0.74–2.20)	0.97 (0.63–1.49)

Values in parentheses are 95% CI. Hearing loss was defined as a PTA >25 dB. The low-frequency method was used with PTA at 0.5, 1, and 2 kHz. Measurement of interaction on an additive scale: RERI = −0.41 (−1.24 to 0.41); p = 0.327. Measurement of interaction on a multiplicative scale: ratio of ORs = 0.70 (0.37 to 1.31); p = 0.264. Models were adjusted for age, sex, monthly income, education level, smoking status, BMI, occupational noise, loud noise, firearm noise, hypertension, and diabetes.