Parental smoking behavior at home and sociodemographic variables may influence exposure to environmental tobacco smoke (ETS) in children. A sample of 115 preschool children aged 3-6 years was enrolled in this study. ETS exposure was evaluated through a questionnaire about parents' smoking behavior and determinations of urinary cotinine F a biomarker of exposure F in children. Bivariate and multiple regression analyses were used to evaluate the association between the smoking behavior of each parent at home, sociodemographic factors and cotinine levels in children. The parental perception of smokiness in the home was significantly associated with urinary cotinine in children (r-partial coefficient ¼ 0.324; Po0.002). The father's education, mother's smoking status, and day of the week when urine was sampled (Tuesday) were also independently associated with levels of cotinine. These four variables explained 26.4% of the variance in the cotinine levels of children. In designing educational programs to reduce passive smoking among children, it is necessary to take into account those factors related with cotinine levels in children. Our results support the influence of the mothers' smoking status, the fathers' educational level, and the day of the week of sampling on cotinine in children. The perception of parents (smokers and nonsmokers) about the smokiness in the home could also be a useful indicator of the cotinine in children exposed to environmental tobacco smoke in the household.

No abstract

The study of the dose-response relationship of disinfectants is of great importance in treating infection, the objective being to use concentrations above the minimal bactericidal concentration (MBC). Below these concentrations, the bacteriostatic or bactericidal effect may be insufficient. Moreover, at low concentrations, a hormetic effect may be observed, producing a stimulation of growth instead of inhibitory action. Hormesis is not well known in the context of antimicrobial substances. This study investigates the possible existence of a hormetic effect in three commonly used antiseptics-chlorhexidine digluconate, povidone iodine and benzalkonium chloride-on strains of reference of Staphylococcus aureus and Pseudomonas aeruginosa. Growth curves were determined for different concentrations of the disinfectants. The variables studied-concentration of disinfectant, instantaneous growth rate and number of generations-were analysed using linear, quadratic and cubic models to adjust for the variables. The three disinfectants tested show a significant hormetic effect with P. aeruginosa and a less significant effect with S. aureus. These findings point to a dose-response effect that is not linear at low concentrations, while hormetic effects observed at some low concentrations result in greater bacterial growth. In infected wounds, materials or surfaces where microorganisms may occupy zones of difficult access for a disinfectant, the hormetic effect may have important consequences.

ABSTRACT:When surface water is used to supply urban settlements, exhaustive studies of the composition of the source are necessary to ensure its potability, and to assess the possible environmental effects associated with contamination by pesticides. The present study centers on the pesticide content of the waters from a section of the Guadalquivir River and its affluents in southern Spain. At many of the sampling points analyzed, high concentrations of both organochlorine and organophosphorus pesticides were detected.The presence of these toxic substances in dangerously high concentrations, as well as the linear tendency of the mean values for total pesticide concentration at sampling points, allows us to conclude that the agricultural character of this area has ultimately contributed to the contamination of the Guadalquivir River and its affluents, creating a sanitary and ecological hazard. In some cases the levels of contamination were found to consistently exceed the limits established by the European Union concerning water quality for human consumption.Because the substances analyzed are not eliminated through conventional water treatment methods, we conclude that the sampled section of the Guadalquivir River basin should not be currently used as a source of water for human consumption. Both pretreatment and advanced water treatment techniques would be required to reduce micropollutant concentrations to potable levels.

The main objective of this study was to assess whether the capacity of Neisseria meningitidis to release endotoxin depends upon the type of strain or upon bacterial mass. Endotoxin release was studied in 32 strains isolated from patients with meningococcal infections and in 49 from asymptomatic carriers, using a quantitative test (limulus test with a chromogenic substrate). The results show that the strains from patients release significantly higher amounts of endotoxin than strains from carriers regardless of serogroup and isolation site. No correlation was found between stage of bacterial growth and the amount of endotoxin liberated. These findings suggest that endotoxin liberation is a characteristic of certain strains of N. meningitidis and is not determined simply by bacterial mass.

Significance and Impact of the Study: The choice of an adequate neutralizing agent is essential for obtaining precise results in the evaluation of disinfectants using the dilution-neutralization method. In this study, we show that the neutralization of triclosan and some of its commercial solutions is not a simple task, requiring complex neutralizers. Moreover, the action of the neutralizer is shown to depend on the micro-organism tested. Specificity in view of the disinfectant and the micro-organism calls for performing the neutralizing assay in each particular case of application of the dilution-neutralization method. We also demonstrate that some of the neutralizers described for triclosan in previous studies are not sufficiently effective. AbstractOne of the most commonly used methods for assessing disinfectants in vitro is the dilution-neutralization test. Although it is known that using an effective neutralizer is essential for obtaining reliable results, in the case of disinfectants like triclosan, whose neutralization is more complicated, an adequate neutralizer is not always used. Here, we compare the efficacy of different neutralizers described previously, and others that have been modified, against several antiseptic formulations of triclosan. The strains of reference used were Pseudomonas aeruginosa, Enterococcus faecium, Staphylococcus aureus and Escherichia coli. The solutions of antiseptic were triclosan 2% aqueous solution, and three alcoholic solutions containing 2, 0Á068 and 0Á5% triclosan, respectively. In the dilution-neutralization test, six neutralizers with different degrees of complexity were assayed. Our results show that the antiseptic solutions studied are effective against the strains of reference, with the exception of triclosan 2% aqueous solution against Ps. aeruginosa. Most neutralizers proved ineffective, depending on the antiseptic solution and the bacterial species, particularly in the case of Staph. aureus. These findings confirm a need to test every neutralizer specifically for each disinfectant, at the maximum concentration used, and for every specific bacterial strain.

When surface water is used to supply urban settlements, exhaustive studies of the composition of the source are necessary to ensure its potability, and to assess the possible environmental effects associated with contamination by pesticides. The present study centers on the pesticide content of the waters from a section of the Guadalquivir River and its affluents in southern Spain. At many of the sampling points analyzed, high concentrations of both organochlorine and organophosphorus pesticides were detected. The presence of these toxic substances in dangerously high concentrations, as well as the linear tendency of the mean values for total pesticide concentration at sampling points, allows us to conclude that the agricultural character of this area has ultimately contributed to the contamination of the Guadalquivir River and its affluents, creating a sanitary and ecological hazard. In some cases the levels of contamination were found to consistently exceed the limits established by the European Union concerning water quality for human consumption. Because the substances analyzed are not eliminated through conventional water treatment methods, we conclude that the sampled section of the Guadalquivir River basin should not be currently used as a source of water for human consumption. Both pretreatment and advanced water treatment techniques would be required to reduce micropollutant concentrations to potable levels. ©1997 by John Wiley & Sons, Inc. Environ Toxicol Water Qual 12: 249–256, 1997

The questionnaire shows high internal consistency. We have obtained a valid tool for assessing risk behavior, knowledge and attitudes about students' hand hygiene in health sciences. The tool detects deficiencies in basic skills in students.