Identification of soil contamination hotspots with veterinary antibiotics using heavy metal concentrations and leaching data—a field study in China

Abstract

In regions with high livestock densities, the usage of antibiotics and metals for veterinary purposes or as growth promoters poses a risk in manured soils. We investigated to which degree the concentrations and depth distributions of Cu, Zn, Cr and As could be used as a tracer to discover contaminations with sulfonamides, tetracyclines and fluoroquinolones. Besides, we estimated the potential vertical translocation of antibiotics and compared the results to measured data. In the peri-urban region of Beijing, China, soil was sampled from agricultural fields and a dry riverbed contaminated by organic waste disposal. The antibiotic concentrations reached 110 μg kg(-1) sulfamethazine, 111 μg kg(-1) chlortetracycline and 62 μg kg(-1) enrofloxacin in the topsoil of agricultural fields. Intriguingly, total concentrations of Cu, Zn, Cr and As were smaller than 65, 130, 36 and 10 mg kg(-1) in surface soil, respectively, therewith fulfilling Chinese quality standards. Correlations between sulfamethazine concentrations and Cu or Zn suggest that in regions with high manure applications, one might use the frequently existing monitoring data for metals to identify potential pollution hotspots for antibiotics in topsoils. In the subsoils, we found sulfamethazine down to ≥2 m depth on agricultural sites and down to ≥4 m depth in the riverbed. As no translocation of metals was observed, subsoil antibiotic contamination could not be predicted from metal data. Nevertheless, sulfonamide stocks in the subsoil could be estimated with an accuracy of 35-200 % from fertilisation data and potential leaching rates. While this may not be sufficient for precise prediction of antibiotic exposure, it may very well be useful for the pre-identification of risk hotspots for subsequent in-depth assessment studies.

Occurrence and distribution of antibiotics in urban soil in Beijing and Shanghai, China

“…Among five detected SAs, SMX revealed the highest average concentration of 0.57 μg kg −1 dw and detection frequency of 44 %. This result was consistent with several previous reports with the low concentration of SAs in the surface soil (Karcı and Balcıoğlu 2009;Tamtam et al 2011), whereas Ostermann et al (2014) have found significantly higher SAs concentration (110 μg kg −1 ) in the topsoil of agricultural fields in the peri-urban region of Beijing, China. As for MLs, much lower concentration and detection frequency than SAs in the urban soil was observed, and ROX was detected with maximum detection frequency of 26 % and average concentration of 0.06 μg kg −1 dw.…”

“…The concentrations of SMX and ROX in our study were higher than those in the agriculture soil after long-term wastewater irrigation in Paris (Tamtam et al 2011) and in the agriculture soil fertilized with poultry or cattle manure (Karcı and Balcıoğlu 2009), but lower than the SMX concentration of 4 μg kg −1 determined in peri-urban agricultural soil after approximately 20 years irrigation with untreated wastewater in Mexico City (Dalkmann et al 2012). In contrast, (Ostermann et al 2014) have found a maximum SMZ concentration of 110 μg kg −1 in peri-urban agricultural soil from Beijing, while SMZ was only detected with the maximum concentration of 2.8 μg kg −1 in urban soil from Beijing and Shanghai in our study.…”

“…These concentrations were lower than those in the sludge-treated soil in Switzerland (Golet et al 2002), but higher than those detected at organic vegetable bases and suburban areas in Tianjin, China (Hu et al 2010), as well as higher than those in peri-urban agricultural soil after longterm wastewater irrigation in Tianjin, China , Paris (Tamtam et al 2011), and Mexico City (Dalkmann et al 2012). In addition, Ostermann et al (2014) have detected the maximum ENR concentration of 63 μg kg −1 in peri-urban agricultural soil from Beijing, which was also lower than that of 128 μg kg −1 in our study. An important reason for the high concentrations found in the urban soil is probably that these soils are not mixed regularly by plowing.…”

“…However, to some extent, such management may result in negative consequences such as organic or inorganic contamination of soil. Several studies have been conducted to explore the occurrence and fate of antibiotics in the agricultural soil after long-term wastewater irrigation or fertilization using animal manure (Dalkmann et al 2012;Hamscher et al 2002;Hu et al 2010;Karcı and Balcıoğlu 2009;Kinney et al 2006;Ostermann et al 2014;Shi et al 2012;Siemens et al 2010;Tamtam et al 2011;Ternes et al 2007). However, the studies on the occurrence and distribution of antibiotics in urban soil are still less reported.…”

Improving manure nutrient management towards sustainable agricultural intensification in China

“…There is already clear evidence of overuse of nutrients in some parts of China (SAIN, 2010) and this is causing undesirable impacts on the environment (Norse, 2015;Guo et al, 2010;Le et al, 2010;, with key problems associated with the discharge of effluent (including the liquid fraction of solid manure, whole slurry and the liquid fraction from separated slurry) from livestock farms and over-application to many crop types in China Lu et al, 2012;Sims et al, 2013;Xue et al, 2013b;Yan et al, 2013;Ostermann et al, 2014;Powlson et al, 2014). A more rational approach to the use of nutrients in Chinese agriculture, especially an improvement in manure nutrient efficiency should result in reduced inorganic N fertiliser use, which would deliver a range of benefits, including a reduced impact on the environment and improved farmer incomes, without crop yield penalties.…”