Lead (Pb) exposure from outdoor air pollution: a potential risk factor for cervical intraepithelial neoplasia related to HPV genotypes

Human papillomavirus genotypes (HPVs) have been confirmed to be the major cause of cervical intraepithelial neoplasia (CIN) that remains to be one of the most common women cancers around the world. It seems other risk factors have synergistic effects on cervical cancer occurrence including smoking, dietary pattern, sexual behavior, ethnicity, epigenetics, and environmental hazardous materials. Our study characterized the potential cancerous role of lead (Pb) as a common toxic environmental pollutant agent on CIN outcomes. Lead concentration was quantified using an atomic absorption spectrometer in liquid-based cytology specimens of 40 CIN-HPV positive subjects, 50 HPV infected non-cancerous cases, and 43 non-HPV infected/non-cancerous women. Pb concentration was 5.5 (4.7–6.4) μg/dL, 4.7 (4.2–8.7) μg/dL, and 4.7 (4.5–5.4) μg/dL in the CIN-HPV positive group, HPV infected non-cancerous cases, and non-HPV infected/non-cancerous group, respectively. The results showed higher Pb concentration is associated with higher risk for cervical malignancy in comparison with non-HPV infected/non-cancerous subjects, after controlling for age effect (aOR = 4.55, 95% CI: 1.55–15.07, P < 0.01). Our finding suggested a direct significant association between Pb accumulation and CIN existence. The consequences need to be further validated by including more relevant risk factors and controlling the confounders for better understating of Pb impact from outdoor air pollution on cervical cancer progression.