Browsing by Author "Vasconcelos, Ana Luisa"
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- Human biomonitoring studies contribution for better public health decisionsPublication . Louro, Henriqueta; Vasconcelos, Ana Luisa; Penque, Deborah; Silva, Maria JoãoThe use of chemicals in a wide spectrum of applications from biomedicine to agriculture has brought undeniable benefits to society. However, it is also important to assess, control and minimize potential costs, in terms of long-term impacts on human health and the environment quality. In order to enable chemicals risk assessment and management based on scientific evidence, it is crucial to know the real exposure of citizens to chemicals as well as their adverse effects on human health. In addition, within the framework of chemicals risk assessment, hazard characterization through in vitro and in vivo studies is also central. In this context, the team has developed biomonitoring and molecular epidemiology studies aimed at exploring interactions between occupational or environmental stressors and the human genome/proteome, as determinants of human diseases. Among these, the characterization of biological effects from occupational exposure to second-hand smoke and the effects of uranium mines and its residues on the population health will be presented to highlight their relevance for public health and environment policies. The results of an ongoing study focused on the genotoxicity of the chemical Di-(iso-nonyl)-cyclohexane-1,2-dicarboxylate (DINCH), which has been applied as a non-aromatic plasticizer to replace other hazardous phthalate plasticizers will illustrate the additional need of toxicological studies for a comprehensive assessment of the potential adverse effects of chemicals on human health. Finally, the objectives of the European Biomonitoring Initiative - HBM4EU (https://www.hbm4eu.eu/) aimed at filling the knowledge gaps and promoting innovative approaches in the area of human exposure to chemicals will be presented, as an example of a multidisciplinary and integrative programme that is expected to support the formulation of better environment and health policies to protect human health.
- Impact of DINCH® in human cells: evaluation of its potential cytotoxic and genotoxic effectsPublication . Vasconcelos, Ana Luisa; Silva, Maria João; Louro, HenriquetaThe chemical Di-(iso-nonyl)-cyclohexane-1,2-dicarboxylate (DINCH) has been applied as a non-aromatic plasticizer and substitute for other phthalate plasticizers such as di-(2-ethylhexyl) phthalate (DEHP) and di-(iso-nonyl) phthalate (DINP), that have shown to have adverse effects. Since DINCH detected in indoor dust has increased after the market introduction of this plasticizer in 2002, the human exposure is a concern. Health-related guidance values have been derived for children and adults, namely 3 mg/L and 4.5 mg/L of DINCH metabolites in the urine, respectively. Recently, the exposure of Portuguese children to DINCH was reported, in spite the low levels detected in children’s urine, which were below the established health guidance levels. Conversely, few studies have addressed the potential toxicity of DINCH but in vivo studies suggest its bioavailability, leading to concerns in respect to systemic exposure or longer term consequences of its use, namely to liver or kidney cells. To contribute to the hazard characterization of DINCH, its potential cytotoxicity and genotoxicity was investigated in human liver cells, following the exposure of HepG2 cells to a range of concentrations of this chemical agent. The methodology included the MTT assay for cytoxicity determination, the comet assay for the detection of DNA damage and the micronucleus assay for determination of chromosomal damage, based on the OECD TG 487 guideline (2016). The results showed that concentrations ranging from 1 to 500 µg/mL were neither cytotoxic following 24h exposure of HepG2 cells, nor had impact on DNA or chromosome damage. Underway studies focus on the effects under the presence of exogenous liver metabolic enzymes (S9 fraction) and on the detection of oxidative DNA damage. Further ongoing investigation is addressing the potential nephrotoxic effects of DINCH using kidney cells.