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

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.

Errors in identifying and expressing emotion in facial expressions, voices, and postures unique to social anxiety.

The purpose of the present study was to see if 7-10-year-old socially anxious children (n = 26) made systematic errors in identifying and sending emotions in facial expressions, paralanguage, and postures as compared with the more random errors of children who were inattentive-hyperactive (n = 21). It was found that socially anxious children made more errors in identifying anger and fear in children's facial expressions and anger in adults' postures and in expressing anger in their own facial expressions than did their inattentive-hyperactive peers. Results suggest that there may be systematic difficulties specifically in visual nonverbal emotion communication that contribute to the personal and social difficulties socially anxious children experience.