Assessment of heavy metal toxicants in the roadside soil along the N-5, National Highway, Pakistan

• Published in: Environmental monitoring and assessment 2011-11, Vol.182 (1-4), p.587-595
• Main Authors: Khan, M. Nasiruddin, Wasim, Agha Arslan, Sarwar, Anila, Rasheed, M. Faisal
• Format: Article
• Language: English
• Subjects: Applied sciences; Atmospheric Protection/Air Quality Control/Air Pollution; Atomic absorption spectrophotometry; Automobiles - statistics & numerical data; Cadmium; Cluster Analysis; Cobalt; Earth and Environmental Science; Earth sciences; Earth, ocean, space; Ecology; Ecotoxicology; Engineering and environment geology. Geothermics; Environment; Environmental Management; Environmental Monitoring; Environmental Pollution - statistics & numerical data; Exact sciences and technology; Hazardous materials; Hazardous wastes; Heavy metal content; Heavy metals; Incineration; Lead; Manganese; Mercury; Metals, Heavy - analysis; Metals, Heavy - toxicity; Monitoring/Environmental Analysis; Motor vehicles; Multivariate analysis; Municipal solid waste; Nickel; Nonpoint source pollution; Pakistan; Pollution; Pollution sources. Measurement results; Pollution, environment geology; Quality control; Rain; Roads & highways; Soil and sediments pollution; Soil contaminants; Soil contamination; Soil Pollutants - analysis; Soil Pollutants - toxicity; Soil pollution; Spectral analysis; Spectrophotometry; Studies; Toxicants; Toxicity; Traffic; Vehicle Emissions - analysis; Vehicle Emissions - toxicity; Waste materials; Zinc
• ISSN: 0167-6369; 1573-2959
• DOI: 10.1007/s10661-011-1899-8

The assessment of the toxicants in roadside soil on regular basis has become extremely essential with the increase in awareness for the metal toxicity in the environment. The present study investigates the presence of toxic metals along National Highway (N-5), Pakistan. Averages of about 1.3 million per month of automobile vehicles ply on this route. Lead (Pb), zinc (Zn), copper (Cu), nickel (Ni), cadmium (Cd), cobalt (Co), manganese (Mn), mercury (Hg), and iron (Fe) were analyzed by atomic absorption spectrophotometry in roadside soil at the nine selected locations along the highway. Strong Pearson correlations ( α  = 0.05) were found between Pb and Zn ( r 2  = 0.887), Fe and Mn ( r 2  = 0.880), Hg and Cd (0.864), Cu and Zn (0.838), and Cu and Pb (0.814). The correlation between the elemental compositions of the main automobile components revealed vehicular traffic as the main non-point source of roadside soil pollution. Extremely high level of mercury, 144.05 mg kg  − 1 , was found at S5. It was revealed that the unregulated incineration and dumping sites of hazardous waste material along N-5 were also responsible for these contaminations. Multivariate analysis on the obtained data also disclosed the same interpretation. Cluster analysis of the data grouped Pb, Zn, and Cu at 85.23% similarity, whereas, Cd, Hg, and Ni were grouped at 78.75% similarity basis. The findings need swift action against the root cause of soil pollution.