An incidence of skeletal fluorosis associated with groundwaters of the maritime carboniferous basin,Gaspé region,Quebec, Canada

Consumption of unusually high concentrations of F^– in groundwaters of the Maria area in the Gaspé peninsula of Quebec have resulted in symptoms of skeletal fluorosis in two members of the population. One of these individuals consumed approximately 50 mg of fluoride per day over a 6 year period before being hospitalized and later diagnosed with skeletal fluorosis. It is estimated that, until this case came to light, approximately 15–20% of the rural population (total approximately 1,600) in the area were consuming groundwaters with F^– levels between 5 and 28 mg L^–1 for at least 6 years. The high concentrations of F^– in well waters of the Maria area occur only in wells completed in Carboniferous sandstone-siltstone-conglomerate sediments that underlie a thick blanket of alluvial-colluvial-glacial overburden. These fluoriferous groundwaters exhibit high Na and HCO₃ ^– contents and low Ca and Mg concentrations compared to those associated with the overburden sediments. The high F levels greatly increase the risk for fluorotic diseases such as skeletal fluorosis and skeletal radiculomyopathy. Wells completed in overburden, although having suboptimal F^– levels are safer for the health of individuals in this region. Effective regulations for well drilling need to be formulated for regions underlain by Carboniferous formations in the Maritime provinces of Canada. In some regions, high F^– levels (10–25 mg L^–1) in groundwaters will seriously affect how, and to what extent, groundwater supplies can be developed for domestic use.To whom correspondence should be addressed.     

The EU-project ERAPharm. Incentives for the further development of guidance documents?

- Triggered by the detection of a large variety of pharmaceuticals in surface waters, soils and groundwaters across the world (e.g. Halling- Sørensen et al. 1998, Daughton & Ternes 1999, Jones et al. 2001, Heberer 2002) and the widespread occurrence of endocrine active compounds and related effects in the environment (e.g. Purdom et al. 1994, Tyler et al. 1998, Vethaak et al. 2002), pharmaceuticals in the environment have become an issue for both the scientific and the public community. During the last few years, our understanding of the fate and effects of pharmaceuticals in the environment has progressed significantly. However, there are still a number of uncertainties concerning the effects of pharmaceuticals on the environment and the assessment of potential exposure (e.g. Hanisch et al. 2004, Salomon 2005). These uncertainties will be addressed by the EU-project ‘Environmental risk assessment of pharmaceuticals’ (ERAPharm). This project, a specific targeted research project, is carried out within the priority ‘Global change and ecosystems’ of the 6th framework programme of the European Union. ERAPharm has started on 1st October 2004; the project duration is three years.     

CHEMICAL PRECIPITATION-COAGULATION FOR ORGANIC COLOR REMOVAL FROM GOUNDWATERS1

ABSTRACT: Many wells produce water that is highly colored by organic substances. Colored water may cause aesthetic, economic, and health problems for the cities using it as a municipal supply. Characterization of water from a number of wells showed that the color causing compounds were hydroxylated aromatic carboxylic acids which were precipitated below pH 4.5 and were almost completely ionized above pH 4.5. Through jar tests, a chemical precipitation-coagulation treatment system was developed. The optimal sequence of chemical addition was alum first, followed by pH adjustment and addition of a polyelectrolyte. Rapid mix tests demonstrated the need for a reaction period after alum and after acid addition, and that the rapid mix time controlled floc size for a given flocculation period. Flocculation tests, varying both the floc time and mean velocity gradient, G, showed that an optimum G exists for each floc time and that the residual color decreased with decreasing values of velocity gradient.     

The Quality of Water Resources in Dalmatia

The purpose of this study was to monitor and record the specific characteristics and properties of most of the important water resources in Dalmatia located in Southern Croatia for a period of 5 years (1998–2002) according to established standards for drinking water. The paper presents a detailed account of their chemical content, the classification and the concentration of salts. The bacteriological pollution levels are indicated by the total coliform bacterial levels (MPN coli/100 mL). The water characteristics are expressed by coefficients, which represent the ratios between water ingredients. The Ca/Mg eq ratio, SO₄/Cl eq ratio and K₁, K₂ for bicarbonate hardness were calculated. The hygienic characteristics of the water samples were expressed by the total coliform bacteria estimation (MPN coli/100 mL), the permanganate consumption (KMnO₄) and biological oxygen demand (BOD₅). Karst waters in Dalmatia are moderately hard, the SO₄/Cl ratio is 0.38–1.6, non-corrosive (K₁ lower than 0.2) and not significantly mineralised (< 500 mg/L minerals). Sulphate waters are generally hard, the SO₄/Cl ratio is higher than 1.6, K₁ is 0.2–0.65. Marine waters are quite hard or hard, particularly at the river estuaries, the SO₄/Cl ratio is lower than 0.38, and K₁ is higher than 0.65. The groundwater and springs in Dalmatia are less polluted than surface waters. A majority of these have a geometric average value of MPN coli < 150/100 mL of water observed in 24 of 42 locations studied. The highest bacteriological pollution was found in nine locations where MPN coli > 1000/100 mL and moderate pollution was found in nine locations where MPN coli is between 150 and 1000/100 mL of water. The physical and chemical parameters determined for the most sources in Dalmatia are safe below the international permissible limits.