Assessment of Occurrence, Ecological and Health Risk of Heavy Metals in Agricultural Soil in Hau Giang Province, Vietnam

Abstract

The study aimed to evaluate the occurrence of some heavy metals in agricultural soil in the Hau Giang province, Vietnam. The geographical accumulation index (Igeo), pollutant load index (PLI) and ecological risk index (RI) are used to assess the pollution levels and potential ecological risks due to the presence of heavy metals in agricultural soil. The results showed that the mean concentrations of Cu, Pb and Zn in the soil ranged from 16. 25-40.32, 18.05-29.92 and 52.78-147.22 mg/kg, respectively, within the limits of QCVN 03-MT:2015/BTNMT. Cluster analysis showed that Pb originated from the process of using fertilizers, especially phosphate fertilizers in farming. Cu and Zn possibly share a common origin from the use of pesticides and fungicides in agricultural production. The Igeo value of Cu, Pb and Zn gradually increases in the order of Cu < Zn < Pb. The PLI (1.03-1.97) reflected that the soil in the study area is moderately polluted. The RI (14.80-25.33) represented a low potential ecological risk. In particular, position D3 had the highest level of pollution and risk among the study sites. Pb had the highest level of accumulation in soil with the highest single ecological risk factor; thus, measures should be taken to limit the source of Pb generation. The results of the study also indicated that ingestion route is the main exposure pathway by which heavy metals can be harmful to humans.

Delineation of city-region boundary in Vietnam: The empirical case of ‘Can Tho City-region’

“…Tran et al, 2019). In a thematic report to Hau Giang's People Committee, H. T. Tran (2019) devised a preliminary approach to delineate sub-regional boundaries in the Mekong Delta Region in two steps. In the first step, a comprehensive evaluation of the simultaneous impacts of climate change, sea level rise and saltwater intrusion in the Mekong Delta Region was carried out to designate the most suitable area for long-term habitation and economic development.…”

“…In addition to that, Can Tho has the comparative advantage in terms of urbanization and connectivity which has been shown to have significant impacts on growth even at regions with a low level of urbanization such as the Mekong Delta Region (Le & Bui, 2020). Noticeably, the term 'Can Tho City-region' has been coined by previous studies though only on the conceptual basis (Tran, 2015, p. 252) or on the basis of identifying the most suitable area for long-term habitation and economic development in the context of climate change (Tran, 2019). To the best of the author's knowledge, this article is the pioneering effort to delineate Can Tho City-region boundary based on estimated economic interactions.…”