Response to a commentary by Wiwanitkit (2011) on a report by Swaddiwudhipong et al. (2011)

The use of synthesized zeolites from power plant rice husk ash obtained from Thailand as adsorbent for cadmium contamination removal from zinc mining

“…Previous studies have 19 found high concentrations of cadmium in the rice field, where rice 20 grain contain up to 284 mg/kg on a dry material base [5], and 21 contamination in water, sediment, fish and shellfish with an 22 average of 50.48 mg/L [6]. People that live in this area have high 23 levels of cadmium in their urine and have experienced kidney and 24 bone damages problems [7]. The World Health Organization 25 (WHO) recommends the permissible cadmium concentration of 26 0.003 mg/L in potable water [8].…”

“…1) in 2003 by the Department of 10 Agriculture (DOA), Ministry of Agriculture (MOA) and Department 11 of Pollution Control (DPC) [1]. Cadmium usually occurs in 12 association with zinc ore and is a by-product of zinc mining.…”