High fluoride and low pH level have been detected in popular flavoured beverages in Malaysia

In children, excessive ingestion of fluoride from different sources including bottled drinking water and flavoured beverages or soft drinks can lead to the development of dental fluorosis. In addition, the pH level of beverages is important. Low pH can cause dental erosion. In this study we explore the fluoride content and pH level of certain popular beverages available in Malaysian supermarkets and hawkers' stalls. Bottled drinking water and selected popular flavoured packet drinks were purchased from a supermarket and the corresponding flavoured hawkers' drinks, from a hawker's stall in Kuala Lumpur. Fluoride and pH of the beverages were determined using digital fluoride meter and digital pH meter respectively. It was found that fluoride content and pH level vary among the beverages. The mean fluoride content in both packet and hawkers' drinks [7.64 +/- 1.88 mg/L, 7.51 +/- 1.60 mg/L, respectively] was approximately 7 times higher than the bottled drinking water [1.05 +/- 0.35 mg/L]. Among the beverages, the tea packet drink was found to contain the highest amount of fluoride [13.02 +/- 0.23 mg/L]. The mean pH of bottled-drinking water was near neutral [6.96 +/- 0.17], but acidic for both supermarket [4.78.00 +/- 0.49] and hawkers' drinks [5.73 +/- 0.24]. The lychee packet drink had the lowest pH level [2.97 +/- 0.03]. Due to the wide variation of the fluoride content and pH level of the drinks tested in this study, it is recommended that steps should be taken to control the fluoride concentration and pH level in beverages if dental fluorosis and erosion are to be prevented

Heavy metals contamination in water and sediments of an urban river in a developing country

Water and sediment samples were collected from 20 location of the Buriganga river of Bangladesh during summer and winter 2009 to determine the spatial distribution, seasonal and temporal variation of different heavy metal contents. Sequential extraction procedure was employed in sediment samples for the geochemical partitioning of the metals. Total trace metal content in water and sediment samples were analyzed and compared with different standard and reference values. Concentration of total chromium, lead, cadmium, zinc, copper, nickel, cobalt and arsenic in water samples were greatly exceeded the toxicity reference values in both season. Concentration of chromium, lead, copper and nickel in sediment samples were mostly higher than that of severe effect level values, at which the sediment is considered heavily polluted. On average 72% chromium, 92% lead, 88% zinc, 73% copper, 63% nickel and 68% of total cobalt were associated with the first three labile sequential extraction phases, which portion is readily bioavailable and might be associated with frequent negative biological effects. Enrichment factor values demonstrated that the lead, cadmium, zinc, chromium and copper in most of the sediment samples were enriched sever to very severely. The pollution load index value for the total area was as high as 21.1 in summer and 24.6 in winter season; while values above one indicates progressive deterioration of the sites and estuarine quality. The extent of heavy metal pollution in the Buriganga river system implies that the condition is much frightening and may severely affect the aquatic ecology of the river

Geochemical distribution of trace metal pollutants in water and sediments of downstream of an urban river

A study was conducted to investigate the trace metal pollution of water and sediments of downstream of Tsurumi River, Yokohama, Japan. Twenty samples of water and sediments were collected from the river starting from Tokyo bay side up to the junction point of the Yagami River, Results show that the mean concentrations of chromium, copper and nickel in water greatly exceed [>100 times] the surface water standard, The concentration of molybdenum and lead was also higher than standard values while iron and manganese was lower than that of surface water standard. The mean concentration of zinc, cupper, cadmium, lead, chromium, vanadium, bromine and iodine was 381,1, 133,0, 1.0,40.8, 102.9, 162.0, 71.5 and 10.6 microg/g sediments, respectively and was greatly exceed the average worldwide shale concentrations and average Japanese river sediment values. However, mean concentration of arsenic, nickel and strontium was 11.0, 36,6 and 164.6 microg/g sediments, respectively which was lower than the average shale value. Other analyzed trace metals, including barium, zirconium, rubidium, yttrium, tin, antimony, cesium, lanthanum, cerium, praseodymium and neodymium were detected in river sediments; the concentration of which was close to the Japan's river sediment average values. Pollution load index values of the sites of the studied area ranged from 1.24 to 7.65 which testify that the river sediments are polluted. The PLI value of the area was, however, high [6.53] as the concentration of trace metals like zinc, copper, cadmium, lead and chromium were very high and were the major pollutants