Daily Archives: July 22, 2015

High Mn-Low Fe in Drinking Water a Risk Factor for Dental Caries

Tsanidou E, Nena E, Rossos A, Lendengolts Z, Nikolaidis C, Tselebonis A, Constantinidis TC. Caries prevalence and manganese and iron levels of drinking water in school children living in a rural/semi-urban region of North-Eastern Greece. Environmental health and preventive medicine 2015 Jul 19.

OBJECTIVE: The aim of this study was to correlate different combinations of manganese (Mn) and iron (Fe) concentration in drinking water with prevalence of dental caries in both primary and permanent dentition, among school children with similar socio-demographic characteristics.

METHODS: Evros region, in North-Eastern Greece, was divided into four areas, according to combinations of levels of Mn and Fe in drinking water (High Mn-high Fe; High Mn-low Fe; Low Mn-high Fe; Low Mn-low Fe). Children of similar socio-economic background, attending either first or sixth grade (primary or permanent dentition, respectively) of elementary schools, were clinically assessed for caries by three dentists. Caries was defined by the use of dmft/DMFT index. A questionnaire answered by the parents was also analysed.

RESULTS: 573 children were included. Caries prevalence was high in both age groups (64.2 % with mean dmft 3.3 ± 3.6 in primary and 60.7 % with mean DMFT 2.3 ± 2.5 in permanent dentition, respectively). Residence in a high Mn-low Fe area was associated with a significant OR for caries in both age groups [OR (95 % CIs) for primary and permanent dentition was, respectively, 3.75 (1.68-8.37), p = 0.001 and 3.09 (1.48-6.44), p = 0.003], independently of factors like sugar consumption or brushing frequency.

CONCLUSION: Prevalence of caries was high in general, and was associated with the combination of high Mn/low Fe levels in drinking water, independently of various socio-demographic factors.

Vatican Cardinal Criticizes Pope Francis’ environmental encyclical

The Pope’s encyclical is clearly an advocacy statement on “climate change” given the sordid history behind its development (look here, here  here and here .

“The Vatican’s financial chief, Cardinal George Pell, has taken the unusual step of criticizing Pope Francis’ groundbreaking environmental encyclical, arguing the Catholic Church has “no particular expertise in science.” “

“… the church has got no mandate from the Lord to pronounce on scientific matters. We believe in the autonomy of science,” Pell told the Financial Times on Thursday (July 16).”

Click here for full article.

Ceramic Pot Filter Design and Construction; Experience Required

With the right equipment and a lot of practice, ceramic pot filters can be made that have acceptable performance. But ceramic pot filters are not practical for every household. In our experience their design and construction is very particular and slight changes the factors mentioned in this article can drastically impact performance. Their appeal lies in the fact that local potters with skill can make them, but not everyone has such skill and equipment. Ceramic pots can also be somewhat fragile and can be broken in transit. Other household water treatment options are available and may be preferred in situations where performance reliability and durability are important.

A. I. A. Soppe, S. G. J. Heijman, I. Gensburger, A. Shantz, D. van Halem, J. Kroesbergen, G. H. Wubbels and P. W. M. H. Smeets. Critical parameters in the production of ceramic pot filters for household water treatment in developing countries  Journal of Water and Health Vol 13 No 2 pp 587–599 2015 doi:10.2166/wh.2014.090

The need to improve the access to safe water is generally recognized for the benefit of public health in developing countries. This study’s objective was to identify critical parameters which are essential for improving the performance of ceramic pot filters (CPFs) as a point-of-use water treatment system. Defining critical production parameters was also relevant to confirm that CPFs with high-flow rates may have the same disinfection capacity as pots with normal flow rates. A pilot unit was built in Cambodia to produce CPFs under controlled and constant conditions. Pots were manufactured from a mixture of clay, laterite and rice husk in a small-scale, gas-fired, temperature-controlled kiln and tested for flow rate, removal efficiency of bacteria and material strength. Flow rate can be increased by increasing pore sizes and by increasing porosity. Pore sizes were increased by using larger rice husk particles and porosity was increased with larger proportions of rice husk in the clay mixture. The main conclusions: larger pore size decreases the removal efficiency of bacteria; higher porosity does not affect the removal efficiency of bacteria, but does influence the strength of pots; flow rates of CPFs can be raised to 10–20 L/hour without a significant decrease in bacterial removal efficiency.