Environmental Pollution Assessment of Heavy Metals in Soils and Crops in Xinping Area of Yunnan Province, China

Abstract

With the development of the economy and society, the environmental problems caused by heavy metals have always been the focus of attention. Strong concern has been recently shown for the heavy metal pollution of soils in southwestern China. The heavy metals of surface soils in the Xinping area of Yunnan province, China are surveyed along with some crop samples. There are 3312 surface soils and 95 crop samples collected in about 370 square kilometers. Heavy metals including As, Cd, Cr, Hg, and Pb and pH are analyzed. New single and integrated pollution indices of heavy metals for soils (PI and PIn) and crops (PIc and PInc) based on Chinese criteria (GB15618-2018 and GB2762-2022) are described and presented here and used to assess the pollution status of heavy metals. The results indicate that the background level of surface soils is about 62.1%, the screening level is about 33.4%, and the intervention level is about 4.5%, which is mainly a result from Cr and spatially coincides with the peridotite rock, indicating a geogenic pollution source. Most crop samples are not contaminated with heavy metals. Comparing the results of the two integrated pollution indices between soils and crops, two inconsistent assessments are observed. One is that some contaminated crops are growing in unpolluted areas (or Type I) and the other is that some uncontaminated crops are growing in polluted areas (or Type II). This indicates a new challenge between the assessment criteria on soils and crops.

Mitreola quanruii (Loganiaceae), a new species from a karst region in Guangxi, China

“…Karst ecosystems are renowned for their distinct vegetation and high biodiversity, offering exceptional habitats that foster speciation and radiation ( Myers et al 2000 ; Biswas 2009 ). The genus Mitreola predominantly comprises limestone obligate and narrowly distributed species ( Yu et al 2017 ; Shan et al 2019 , 2021 ; Wei 2019 ; You et al 2020 ; Liao and Chen 2021 ; Liu et al 2022 ). Notably, recent publications have reported new species of Mitreola exclusively found in the limestone region of southwest China ( Shan et al 2019 , 2021 ; You et al 2020 ; Liao and Chen 2021 ; Liu et al 2022 ).…”

“…Notably, recent publications have reported new species of Mitreola exclusively found in the limestone region of southwest China ( Shan et al 2019 , 2021 ; You et al 2020 ; Liao and Chen 2021 ; Liu et al 2022 ). This region boasts the most extensive karst formations globally and is recognised as one of China’s three unique floristic centres, as well as a vital area for global biodiversity conservation efforts ( Yu et al 2017 ). In recent years, scientists have discovered and documented an increasing number of new plant species, including Annonaceae , Gesneriaceae and Magnoliaceae in this area ( Hu et al 2022 ; Li et al 2022 ; Liu et al 2022 ; Yang et al 2023 ).…”

“…14 species have been recorded in this area so far. Of these, eleven species, most of them found in limestone areas, are endemic to the country ( Fang et al 1995 ; Li and Leeuwenberg 1996 ; Ma et al 2010 ; Yu et al 2017 ; Shan et al 2019 , 2021 ; You et al 2020 ; Liao and Chen 2021 ; Liu et al 2022 ).…”

“…A total of 8,892 native plant species have been recorded in Guangxi, including 889 endemic plant species ( Wei 2019 ). As one of the diversification centres of Mitreola , Guangxi has a total of seven species, amongst which five species are endemic to Guangxi and are karst obligate species ( Yu et al 2017 ; Wei 2019 ).…”

Assessment of Heavy Metal(loid) Pollution and Human Health Risks Associated with a Mineral (Zn, Cu, and Sn Ores) Processing Plant in Yunnan, Southwest China

“…HMs not only damage the surrounding soil through surface water and groundwater seepage and other pathways [30,31], but also cause harm to human health by entering the food chain through agricultural products. Studies on the soil in Yunnan [32][33][34] show varying degrees of HM pollution, emphasizing the importance of evaluating HM pollution originating from the residual land of the mineral processing plant.…”