The valley of Mexicali is one of the most important agricultural areas in the northwest of Mexico. Rapid urbanization has meant that parts of the agricultural channels and drains now lie within the urban area. To evaluate the concentrations of heavy metals in urban drain sediments, thirty-one samples were collected in the Mexicali urban area. Mean concentrations of Cd, Cu, Cr, Fe, Ni, Pb and Zn were 0.28, 70.0, 17.0, 4.48 × 10 .4, 13.5, 32.3 and 229 mg kg^{− 1}, respectively. The geoaccumulation index results indicated that most of the drain sediments were from unpolluted to slightly polluted by heavy metals for most of the sites, with the exception of Cu which had seven sites Class 3, two sites Class 4 and two sites Class 5 and 6, respectively. Similarly, the enrichment factors showed that most of the sites had minimum enrichment.

墨西卡利山谷是墨西哥西北部最重要的农业地区之一。快速的城市化意味着现在部分农业渠道和排水沟都位于市区内。为了评估城市排水沟沉积物中的重金属浓度，在墨西卡利市区收集了31个样品。Cd，Cu，Cr，Fe，Ni，Pb和Zn的平均浓度为0.28、70.0、17.0、4.48×10 .4、13.5、32.3和229 mg kg ^{− 1}， 分别。地质累积指数结果表明，大多数地点的大部分排水沉积物从重金属污染到未污染到轻度污染，除了铜有3个地点，3个地点，4个地点和5和6个地点之外，其余大部分都被重金属污染。分别。同样，富集因子显示大多数站点的富集程度最小。