Analisis Kandungan Logam Berat Timbal (Pb) pada Tanah dan Beras pada Lahan Sawah di Kota Medan

Abstract

This study aims to analyze the content of lead (Pb) heavy metal in soil and rice from paddy fields in Medan City. Lead (Pb) is a toxic heavy metal that can contaminate soil and crops, posing a potential threat to human health. A total of 30 soil and rice samples were collected from various paddy fields across all sub-districts in Medan City. Soil sampling was conducted using a composite method at a depth of 0–20 cm, while rice samples were collected at harvest from the same locations. The Pb content analysis was performed using Atomic Absorption Spectrophotometry (AAS). Observed parameters included Pb levels in soil, Pb levels in rice, soil texture (sand, silt, and clay fractions), and soil cation exchange capacity (CEC).The results showed that Pb levels in soil ranged from 68.5 ppm to 100.6 ppm, categorized as moderate to high. Pb levels in rice were also found to exceed the permissible limit of 0.3 ppm, with an average Pb content of 25.3 ppm. A significant correlation was observed between Pb levels in soil and Pb levels in rice, with a correlation coefficient of 0.564. In contrast, the correlation between Pb levels in rice and soil texture components (sand, silt, and clay fractions) as well as soil CEC showed no significant relationships, with very weak correlation values. Based on these findings, Pb heavy metal contamination in Medan City requires serious attention due to its potential health risks to the community.