Elemental speciation, bioavailability and risk assessment of selected heavy metals in the intertidal surface sediments of Sungai Puloh mangrove, Malaysia - Emeka, Udechukwu Bede; Ismail, Ahmad; Zulkifli, Syaizwan Zahmir; Omar, Hishamuddin (Department of Biology, Faculty of Science, Universiti Putra Malaysia, 2014)