Traditional Khol as a Potential Source of Lead Exposure in the Algerian Population

Background Kohl is a traditional eye cosmetic widely used in North Africa, the Middle East, and South Asia for aesthetic, cultural, and perceived therapeutic purposes. While historically composed of antimony trisulfide (stibnite), many modern products contain lead sulfide (galena), resulting in extremely high lead concentrations. Because lead has no safe exposure threshold, kohl may represent a significant source of systemic exposure. This study evaluated the association between kohl use and blood lead levels (BLLs) in the Algerian population. Methods A national descriptive cross-sectional biomonitoring survey was conducted in Algeria between 2017 and 2019. A total of 3,674 participants from 121 districts across 39 provinces were included. Participants completed a standardized questionnaire documenting kohl use frequency (daily, weekly, occasional, or never), underwent clinical examination, and provided venous blood samples. Blood lead concentrations were measured by inductively coupled plasma mass spectrometry (ICP-MS) using a PerkinElmer NexION 300-X instrument (quantification range 5–1000 µg/L; LOD 1.67 µg/L). Statistical analyses were performed using IBM SPSS Statistics v21, comparing mean BLLs across exposure categories with 95% confidence intervals. Results Overall, 33.7% of participants reported using kohl at least occasionally, predominantly adult women. Occasional use was most frequent (19.2%), followed by daily (6.5%) and weekly (5.8%) use. The mean BLL was 28.27 µg/L (median 22.22 µg/L; range 0.8–602.92 µg/L). Daily users showed the highest mean BLL (38.42 µg/L; 95% CI 31.96–44.88), significantly higher than weekly (28.14 µg/L), occasional (25.44 µg/L), and non-users (28.55 µg/L) (P < 0.0001). The highest BLL (602.9 µg/L) occurred in a woman reporting daily kohl use. Conclusions Kohl use is common in Algeria and is associated with increased BLLs, particularly among frequent users. These findings highlight kohl as a potential contributor to lead exposure and support the need for strengthened regulation, public health awareness, and preventive strategies.