Environmental exposure of heavy metal (lead and cadmium) and hearing loss: data from the Korea National Health and Nutrition Examination Survey (KNHANES 2010–2013)

Table 1 General characteristics of the study population

Variables	Total n^a	Male	Female	p-value^b
Total	6409	3185	3224
Age (years)
Mean ± SE	47.1 ± 0.3	46.3 ± 0.3	48.0 ± 0.3	< 0.001
20–29	1025	493	532	0.002
30–39	1081	537	544
40–49	1415	709	706
50–59	1454	717	737
60–69	1232	615	617
70–87	202	114	88
BMI (kg/m²)
Mean ± SE	23.8 ± 0.1	24.2 ± 0.1	23.5 ± 0.1	< 0.001
Underweight	246	68	178	< 0.001
Normal	4071	1936	2135
Obese	2092	1181	911
Education
≤ Middle school	1861	751	1110	< 0.001
High school	2365	1226	1139
≥ College	2183	1208	975
Smoking
Non-smoker	3650	723	2927	< 0.001
Ex-smoker	1176	1063	113
Current smoker	1583	1399	184
Alcohol
None	638	104	534	< 0.001
Light drinker	4128	1923	2205
Heavy drinker	1643	1158	485
Exercise
No	4771	2271	2500	< 0.001
Yes	1638	914	724
Current diagnosis of diabetes mellitus
No	5980	2936	3044	0.069
Yes	429	249	180
Current diagnosis of hypertension
No	5237	2573	2664	0.202
Yes	1172	612	560
Occupational noise exposure
No	5496	2538	2958	< 0.001
Yes	913	647	266
Loud noise exposure
No	6267	3095	3172	0.008
Yes	142	90	52
Firearm noise exposure
No	4750	1642	3108	< 0.001
Yes	1659	1543	116

ISSN: 2052-4374