No abstract

The concentration and impact of 1,1,1-trichloro-2,2-bis(4-chlorophenyl)-ethane (DDT) and its metabolites (DDE: 1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene) on the environment was expected to decrease after its ban in the mid-1980s. Unfortunately, DDT contamination via its presence as an impurity in dicofol (2,2,2-trichloro-1,1-bis(4-chlorophenyl)ethanol) has led to a new source of contamination. This is particularly true especially in cotton production in Söke Plain, Turkey, where difocol-based pesticides are being used. The aim of this research was to investigate the extent and source of DDT contamination in cotton soils. Söke Plain soil samples were collected from 0-30, 30-60, and 60-90-cm depth and analyzed by GC/MS/MS. o,p'-DDT and p, p'-DDE were detected at 16.2 % and 17.6 % of the sites in the 0-30-cm depth of soils. In the 30-60 cm, p, p'-DDT (14.9 %), o, p'-DDE (8.1 %) and p, p'-DDE (2.7 %) were found in soil samples, and p, p'-DDT was the most prevalent with 9.5 % of the sampling sites. The dominant source of DDT particularly in the 60-90-cm depth was due to historic use of DDT. The presence of p, p'-DDE, o, p'-DDE and p,p'-DDT in the topsoil was attributed to recent dicofol applications.

Pesticide residues are always an unsolved problem in the world despite all kinds of prevention measures. The present research work is based on a scientific hypothesis, i.e., "The removal of average pesticide residue is inversely proportional to the thickness of cuticle." The effects of boron-containing products and plant-based surfactants were tested for the removal of five pesticides (lambda-cyhalothrin, chlorpyrifos, diflubenzuron, metaflumizone, acetamiprid) on tomatoes and apples. Boron-containing products were able to remove the pesticide residues on average between 58.0 and 72.6% in tomatoes and 33.2-58.8% in an apple. While plant-based surfactants removed residues on average between 58.5 and 66.6% in tomatoes and 41.0-53.2% in an apple. The highest removal rate was 72% with etidot at 1%. The solution of 1% C8-C10 provided 66.6% average removal for tomatoes. Less removal was achieved in apples. For an apple, Log K ow and molecular mass (independent variables) were significant with p < 0.01, and the coefficient of determination (R 2 ) was > 0.87. However, the multiple linear regression analysis for ground colemanite was significant with R 2 of 0.96. In tomatoes, neither Log K ow nor molecular mass as significant. The correlation was found between the physical and chemical properties of pesticides, but it is estimated that the thickness of the cuticle is effective in removing pesticides.

Toplum sağlığı açısından risk taşıyan ve gıda kaynaklı bir patojen olan Escherichia coli O157:H7 önemli ve tehlikeli mikroorganizmalardan birisidir. Patojenin bulaşma yollarının bilinmesi, yayılmayı önleyici tedbirlerin tam olarak anlaşılması ve bulaşma riskinin azalma yollarının tespiti insanların bu patojenden korumada en önemli kriterlerdendir. Bu çalışmada patojenin tam olarak kaynaklarının bilinmesi, bulaşma yolları ve yayılmasını engellemede güncel çalışmaları kullanarak kişilerin bu patojen kaynaklı rahatsızlıkların önüne geçilmesine yardımcı olmak amaçlanmıştır. Konuyla ilgili olarak son dönemlerde yapılmış olan çalışmalar incelendiğinde etmenin bulaşma yollarına dikkat çekilmiş, özellikle iyi pişirilmemiş et ürünlerinin tüketimi, pastörize edilmemiş süt tüketimi, kontamine olmuş havuz ya da göl sularında yüzmek dünyada görülen enfeksiyonların sebebi olmasından dolayı bulaşma riskini ortadan kaldırmak ve hastalıktan korunmaya yardımcı olmak adına yaşam kalitesini artırıcı etkisi bulunan konular üzerinde önem kazanmıştır.

In this study, the presence of Escherichia coli O157:H7 was investigated for the first time in lettuce samples taken from the neighborhood markets and markets in Aydın, and isolation and identification studies were carried out. Since E. coli O157:H7, which is important for public health, is one of the food-borne pathogenic microorganisms, it is aimed to create an important data source for regions with similar climatic characteristics with the prevalence and contamination status of the pathogen. As a result of isolation and identification studies of 100 lettuce samples taken from neighborhood markets and markets, a total of 17 (17%) E. coli O157:H7 samples were isolated and identified from all samples, 12 (12%) of pathogens were from markets, 5 (5%) were were obtained from samples taken from the markets. In line with the results obtained, it was stated that while the lettuce purchased from markets and markets poses a risk in terms of the presence of E. coli O157:H7, it is stated that preventive measures should be taken in the stages of cultivation, fertilization, irrigation, transportation and storage.