Relation between pesticide exposure and intrauterine growth retardation

The increased use of organophosphorus insecticides in agriculture and their widespread existence in the environment poses a potential health hazard. To determine the relationship between exposure to pesticides and intrauterine growth retardation (IUGR), live newborns from singleton pregnancies, with (n = 79) and without (n = 292) IUGR were studied. During the gestational period the mothers were living in agricultural communities in the state of Chihuahua, Mexico. Exposure to agrochemical products was evaluated. A significant association between the history of positive exposure to pesticides (i.e. the women themselves or their newborns who showed acetylcholinesterase activity levels lower than 20%) and the presence of IUGR was found. The proportions of exposure in the cases were 18% and 8% in the control group; the adjusted OR (fat free mass, anti-cytomegalovirus antibodies and placental weight) was 2.33 (p = 0.04).     

A study of the dental solid waste produced in a school of dentistry in Turkey

Dental wastes are regulated under medical waste control regulations in most countries. Even though the quantity of hazardous wastes in dental solid wastes is a small proportion, there is still cross infection risk and potential danger for environment associated with mismanaged wastes. For this reason, knowledge of waste composition and development of proper management alternatives are necessary. In this study, the composition of solid wastes coming from eight clinics of the dental school of a University hospital in Turkey is examined. Although the waste has some variations between the two samplings, the general picture is such that the major components remain pretty much the same (in terms of %) for a fixed clinic. The composition of waste changes from one clinic to the other as expected. However, one can deduce from the data obtained that at about 35%, rubber gloves constitute close to the half of the total solid waste in almost all the clinics. Other major component is paper forming approximately 30% of the solid waste. In general, total waste coming from the clinics is related with the number of procedures conducted on patients at the clinics. Only a small fraction of the waste is hazardous indicating that at Hacettepe University School of Dentistry, hazardous waste collection rules are obeyed in most of the times.     

Guluronic acid content as a factor affecting turbidity removal potential of alginate

Alginates are natural polymers composed of mannuronic and guluronic acid residues. They are currently extracted from brown algae; however, alginate can also be synthesized by some species of Azotobacter and Pseudomonas. Alginates with different proportion of mannuronic and guluronic acids are known to have different characteristics and form gels at different extents in the presence of calcium ions. The aim of this work was to investigate the usefulness of alginate as a non-toxic coagulant used in purification of drinking water. This study utilized alginates from Azotobacter vinelandii having different guluronic acid levels. These were obtained partly by changing the cultivation parameters, partly by epimerizing a purified alginate sample in vitro using the A. vinelandii mannuronan C-5 epimerase AlgE1. The different alginates were then used for coagulation together with calcium. The results showed that turbidity removal capability was dependent on the content of guluronic acid residues. For the best performing samples, the turbidity decreased from 10 NTU to 1 NTU by the use of only 2 mg/L of alginate and 1.5 mM of calcium chloride.