Statistical Approach to Identify Environmental Factors in Controlling Heavy Metal Concentrations in Sediment

Surface sediment samples were collected from 35 locations in Sulaibikhat Bay, Kuwait. Co, Cr, Cu, Ni, Pb and Zn concentrations were determined. Grain sizes, TOC （total organic carbon）, carbonate, mineralogical and environmental data were also determined. Multiple linear regression is applied to the data from the sediment sequential extractions to assess the relative importance of mineralogical and sedimentological factors in controlling heavy metal concentrations in individual chemical fractions （exchangeable, reducible, oxidizable, residual） under different environmental conditions. The analysis shows that grain size, TOC, calcium carbonate and minerals clearly influence heavy metal concentrations. For the exchangeable fraction, clay, grain size and the mineral pyrite are the main factors, whereas for the reducible fraction, TOC is the main factor influencing concentrations ofZn, Pb, Ni, Cu and Cr. For the oxidizable fraction, modelling shows that TOC is the main factor influencing Zn, Ni, Cu, Cr and Co concentrations. The residual fraction concentrations of Zn, Ni, Cr and Co were best predicted by the abundance of sand, with sand content having a negative effect on heavy metal concentrations in this fraction. The statistical techniques in environmental data interpretation are quite useful in cutting down the volume of the data and identifying identical classes which are statistically distinct.

Inventories and assessment of POPs in the State of Kuwait as a basis for Stockholm Convention implementation

Since 2006,Kuwait has been a party to the Stockholm Convention(SC)on Persistent Organic Pollutants(POPs).According to Article 7 of the SC,each party should develop a National Implementation Plan(NIP)and endeavour to implement the plan for the control and elimination of POPs.A first detailed National Implementation Plan has been developed for Kuwait with the support of the Stockholm Convention Regional Center for Capacity-Building and the Transfer of Technology for West Asia(SCRC Kuwait)in KISR.It includes a detailed action plan to manage and control the POPs in the country but also with activities to further give regional support for POPs monitoring and management.The current paper discusses the major inventory findings for the individual POPs groups including POPs pesticides,polychlorinated biphenyls(PCBs),polybrominated diphenyl ethers,and hexabromocyclododecane(HBCD)as well as Perfluorooctanesulfonic acid(PFOS)and unintentional POPs.Besides,information from POPs monitoring studies in Kuwait relevant to the NIP is shortly compiled for further informing on the current situation of POPs in Kuwait.Selected soil samples were collected and analyzed for selected POPs during the NIP development to generate supplementary information to the POP monitoring studies already conducted in Kuwait.Further relevant areas for the POPs management and control were assessed during the NIP development and are listed in the paper.One finding in the NIP assessment was that some of the alternatives used are also bioaccumulative with toxicity in biota and that in the NIP implementation.Also,alternative pesticides in the current use are an issue of concern.Therefore one activity in the implementation of the NIP is the avoidance of regrettable alternatives and the use of more sustainable and green chemicals.