Collaborative Assessment and Health Risk of Heavy Metals in Soils and Tea Leaves in the Southwest Region of China

Abstract

The collaborative assessment and health risk evaluation of heavy metals (HMs) enrichment in soils and tea leaves are crucial to guarantee consumer safety. However, in high soil HM geochemical background areas superimposed by human activities, the health risk associated with HMs in soil–tea systems is not clear. This study assessed the HMs concentration (i.e., chromium (Cr), cadmium (Cd), arsenic (As), and lead (Pb)) in tea leaves and their relationship with soil amounts in the southwest region of China to evaluate the associated health risk in adults. The results revealed that the average soil concentration of Cr was the highest (79.06 mg kg−1), followed by Pb (29.27 mg kg−1), As (14.87 mg kg−1), and Cd (0.18 mg kg−1). Approximately 0.71, 4.99, 7.36, and 10.21% of soil samples exceeded the threshold values (NY/T 853-2004) for Pb, Cr, As, and Cd, respectively. Furthermore, the average concentration of Pb, As, and Cd in tea leaves was below the corresponding residue limits, but Cr was above the allowed limits. Correlation analysis revealed that the Pb, Cr, As, and Cd amounts in tea leaves were positively correlated to their soil amounts (p < 0.01) with an R2 of 0.203 **, 0.074 **, 0.036 **, and 0.090 **, respectively. Additionally, approximately 40.38% of the samples were found to be contaminated. Furthermore, spatial distribution statistical analysis revealed that Lancang was moderately contaminated, while Yingjiang, Zhenkang, Yongde, Zhenyuan, Lüchun, Jingdong, Ximeng, and Menglian were slightly contaminated areas. The target hazard quotients (THQ; health risk assessment) of Pb, Cr, As, and Cd and the hazard index (HI) of all the counties were below unity, suggesting unlikely health risks from tea consumption.

Toxic Metal Detection in Various Types of Tea from Certain Regions of China: Spatial Pollution Characteristics and Potential Health Risk Assessment

“…6 Liu et al analyzed heavy metals in tea leaves in the southwest region of Yunnan province, China, and found that the THQs for Cd and As were 0.007 and 0.136, respectively, and the HI value was 0.452. 6 Zhang et al found that Cd and As concentrations were higher in mature tea leaves, ranging from 0.012 to 0.092 and 0.073 to 0.456, than in young tea leaves, where concentrations ranged from 0.040 to 0.087 and 0.189 to 0.453; they also found that the HI in mature tea leaves was above 1 by 38.46% in Guizhou province, China, indicating a potential health risk for adults via the consumption of mature tea infusions. 13 Li et al found that Cd concentrations (0.2 mg/ L) in tea infusions were below the maximum limits, and that the THQ ranged from 2.33 × 10 −5 to 1.47 × 10 −1 and HI from 1.41 × 10 −2 to 3.45 × 10 −1 .…”

“…A THQ value less than 1 indicates an acceptable risk of harmful material exposure from tea, whereas HI < 1, HI > 1, and HI > 1 indicate no obvious negative impact, a high possibility of negative effects, and chronic toxicity, respectively . Liu et al analyzed heavy metals in tea leaves in the southwest region of Yunnan province, China, and found that the THQs for Cd and As were 0.007 and 0.136, respectively, and the HI value was 0.452 .…”

“…A THQ value less than 1 indicates an acceptable risk of harmful material exposure from tea, whereas HI < 1, HI > 1, and HI > 1 indicate no obvious negative impact, a high possibility of negative effects, and chronic toxicity, respectively . Liu et al analyzed heavy metals in tea leaves in the southwest region of Yunnan province, China, and found that the THQs for Cd and As were 0.007 and 0.136, respectively, and the HI value was 0.452 . Zhang et al found that Cd and As concentrations were higher in mature tea leaves, ranging from 0.012 to 0.092 and 0.073 to 0.456, than in young tea leaves, where concentrations ranged from 0.040 to 0.087 and 0.189 to 0.453; they also found that the HI in mature tea leaves was above 1 by 38.46% in Guizhou province, China, indicating a potential health risk for adults via the consumption of mature tea infusions .…”

“…5 The tea plant is an acidophilic plant that is easily enriched with heavy metals; heavy metals from the atmosphere, soil, and fertilizer accumulate and migrate to the parts of the plant used in tea. In recent years, with the acceleration of urbanization in China, emissions from industrial wastewater, pesticides, fertilizers, and automobile exhaust have caused serious pollution of the soil, 6 and the amount of heavy metals entering tea through the soiltea system is increasing. Therefore, it is of great significance to study the content of heavy metals in tea and evaluate its health risks.…”

Cadmium in Rice Is Affected by Fertilizer-Borne Chloride and Sulfate Anions: Long-Term Field Versus Pot Experiments

“…The accuracy of the results was determined by subjecting the data to a Q-test, which removed asymmetrical errors from the observations (n = 3) at a 95% confidence level. The quality of the results was assured by comparing them to standard reference materials for soil (GBW07605) [45] and plants (GBW08513) [46] from the National Research Center for Standards of China. The Cd retrieval percentage from the soil was 94.7%.…”