Journal of Water and Environmental Sciences (Apr 2017)
POLLUTION AND SEA WATER IN THALASSOTHERAPY CENTERS OF TUNISIA (SW MEDITERRANEAN COASTAL)?
Abstract
The practice of thalassotherapy in Tunisia has been possible while applying statement of Decree 92-129 published July 13, 1992 setting standards and conditions for implementation and exploitation of thalassotherapy centers (TCs), modified and replaced by Decree 2001-1081 of May 14, 2001 and Decree 2006-3174 published November 30, 2006 according to Tunisian standard 126.05 (2007). Recently, this Tunisian standard was origin of the international standard ISO 17680. Concerning quality of seawater used by TCs, these standards require the assay: trace metals (cadmium (Cd), lead (Pb), arsenic (As), mercury (Hg), selenium (Se) and chromium (Cr)), total hydrocarbons (THC), polycyclic aromatic hydrocarbons (PAHs), surface active substances to the methylene blue. The legislation (ISO 17680) cited limits concentration not exceeded. Concerning sewage sea water, Decree 3174-2006 of 30 November 2006 requires that seawater discharged into the marine environment, complies with the Tunisian standard NT 106 002 on liquid discharges in the receiving environment. In part, through the application of these standards, Tunisia was, after France, second destination for thalassotherapy. Thus, to maintain this privileged position and even more advanced in this field, the National Office of Thermalism and Hydrotherapy (NOTH) applied standards ISO 17680 and monitored pollutants concentrations of sea water, which is the main tool for working thalassotherapy centers (TCs). Hence, this study is the first, nationally and internationally, assessing the impact of anionic detergents, heavy metals (cadmium (Cd, Pb, As, Hg, Se and Cr), total hydrocarbons (THC) and detergents (anionic substances) on seawater quality used by six TCs situated in four coastal regions from north to south (Hammamet, Sousse, Monastir and Mehdia) during four months (from May to September 2014). The pollutants concentrations monitored varying among TCs and months. Indeed, Cd concentrations ranged from 1 to 5.10-3 mg.l-1, Pb from 1 to 5.10-2 mg.l-1, Cr from 1 to 17.10-2 mg.l-1 and Hg from 0.2.10-3 to 71.10-2 mg.l-1. Arsenic, Se and anionic detergents concentrations were reached 2, 4 and 10.10-2 mg.l-1, respectively in different TCs. Concentrations of total hydrocarbons were below 0.1 mg.l-1 in the majority of TCs and finally anionic detergents measured in sewages TCs reached respectively 5.08 and 0.3mg.l-1 in sewages TCs B and C. The factorial correspondence analysis (FCA) showed 3 distinct groups: The FCA has shown that concentrations of the highest total hydrocarbons were registered in TCs A, B, E and F. The second group is represented by center C which is characterized by the highest Hg concentrations and the third group represented mainly by single CT D. The latter group was characterized by the highest concentrations of Cr and Pb and the least concentration of Cd. Except anion detergents in sea water, the other pollutants (Cd, Pb, Cr, Hg and THC) exceeded concentrations recorded in the Mediterranean. The presence of these pollutants in the marine environment is due to wastes industrial, agricultural, to geochemical structure and mining) and directly by rivers, and precipitations or atmospheric deposits. Thus, we must be vigilant on these pollutants concentrations and their origins. Besides, the NOTH has taken the necessary measures for items that have exceeded the limits set by the standards concentrations, such as Hg and anionic detergents in sewage TCs. Indeed, except the latter two pollutants, Cd, Pb, Cr, As, anionic detergents and THC have not exceeded the limits set by the standard concentrations.
