Integrating bioassays and analytical chemistry as an improved approach to support safety assessment of food contact materials.

Food contact materials (FCM) contain chemicals which can migrate into food and result in human exposure. Although it is mandatory to ensure that migration does not endanger human health, there is still no consensus on how to pragmatically assess the safety of FCM since traditional approaches would require extensive toxicological and analytical testing which are expensive and time consuming. Recently, the combination of bioassays, analytical chemistry and risk assessment has been promoted as a new paradigm to identify toxicologically relevant molecules and address safety issues. However, there has been debate on the actual value of bioassays in that framework. In the present work, a FCM anticipated to release the endocrine active chemical 4-nonyphenol (4NP) was used as a model. In a migration study, the leaching of 4NP was confirmed by LC-MS/MS and GC-MS. This was correlated with an increase in both estrogenic and anti-androgenic activities as measured with bioassays. A standard risk assessment indicated that according to the food intake scenario applied, the level of 4NP measured was lower, close or slightly above the acceptable daily intake. Altogether these results show that bioassays could reveal the presence of an endocrine active chemical in a real-case FCM migration study. The levels reported were relevant for safety assessment. In addition, this work also highlighted that bioactivity measured in migrate does not necessarily represent a safety issue. In conclusion, together with analytics, bioassays contribute to identify toxicologically relevant molecules leaching from FCM and enable improved safety assessment.

[Smoking and student survival at Universidad Santiago de Cali, 2004-2007]. / Tabaquismo y supervivencia estudiantil en la Universidad Santiago de Cali. 2004-2007.

OBJECTIVE: This article presents the results of monitoring students who enrolled at Universidad Santiago de Cali (USC) during the second half of 2004. Its purpose was to determine the influence of smoking, the academic programme and the cost of enrollment on student survival over a three-year period (2004-2007). METHOD: The study involved a prospective cohort of 970 students who entered the university in 2004. Cox regression was used for survival analysis to determine the relationship between independent variables and university stay. RESULTS: The results of this model established associations between smoking and department with survival in the university, but discarded association with the cost of enrollment. The risk of university desertion was higher amongst students from the Health faculty adjusted for smoking (RR = 1.277 (1.121-1.455)). Similarly, the risk of desertion was higher in smokers adjusted by faculty (RR = 1.194 (1.026-1.390). CONCLUSIONS: It was found that habitual smokers had shorter university stay than nonsmokers. University stay was longer in students enrolled in academic programmes other than health.

Tabaquismo y supervivencia estudiantil en la Universidad Santiago de Cali. 2004-2007 / Smoking and student survival at Universidad Santiago de Cali, 2004-2007

Objetivos Este artículo presenta los resultados del seguimiento de los estudiantes ingresados y matriculados en la Universidad Santiago de Cali USC en el segundo semestre de 2004. El propósito fue determinar la influencia del tabaquismo, el programa académico y el costo de la matrícula en la supervivencia como estudiantes en la universidad durante un período de tres años 2004-2007. Método El estudio fue de cohorte prospectiva sobre el grupo de 970 estudiantes que ingresaron en el año 2004. Para determinar la relación entre las variables independientes y la supervivencia universitaria, se realizó análisis de supervivencia a través de la regresión de Cox. Resultados Los resultados del modelo establecieron asociaciones entre tabaquismo y Facultad descartando costos de matrícula. El riesgo de deserción es mayor entre estudiantes de la facultad de Salud ajustado por tabaquismo (RR= 1,3 (1,1- 1.5)). De manera similar el riesgo es mayor en los fumadores ajustado por la Facultad (RR= 1,2 (1,1-1,4)). Conclusiones Se encontró que los fumadores habituales permanecen menos en la universidad que los no fumadores. La supervivencia universitaria fue mayor en los programas académicos diferentes al área de la salud.

Objective This article presents the results of monitoring students who enrolled at Universidad Santiago de Cali (USC) during the second half of 2004. Its purpose was to determine the influence of smoking, the academic programme and the cost of enrolment on student survival over a three-year period (2004-2007). Method The study involved a prospective cohort of 970 students who entered the university in 2004. Cox regression was used for survival analysis to determine the relationship between independent variables and university stay. Results The results of this model established associations between smoking and department with survival in the university, but discarded association with the cost of enrolment. The risk of university desertion was higher amongst students from the Health faculty adjusted for smoking (RR = 1.277 (1.121-1.455)). Similarly, the risk of desertion was higher in smokers adjusted by faculty (RR = 1.194 (1.026-1.390). Conclusions It was found that habitual smokers had shorter university stay than nonsmokers. University stay was longer in students enrolled in academic programmes other than health.