Application of an in vitro new approach methodology to determine relative cancer potency factors of air pollutants based on whole mixtures.

Air pollution is an example of a complex environmental mixture with different biological activities, making risk assessment challenging. Current cancer risk assessment strategies that focus on individual pollutants may overlook interactions among them, potentially underestimating health risks. Therefore, a shift towards the evaluation of whole mixtures is essential for accurate risk assessment.

Antagonistic effects of a COX1/2 inhibitor drug in human HepG2 cells exposed to an environmental carcinogen.

Understanding interactions between legacy and emerging environmental contaminants has important implications for risk assessment, especially when mutagens and carcinogens are involved, whose critical effects are chronic and therefore difficult to predict. The current work aimed to investigate potential interactions between benzo[a]pyrene (B[a]P), a carcinogenic polycyclic aromatic hydrocarbon and legacy pollutant, and diclofenac (DFC), a non-steroidal anti-inflammatory drug and pollutant of emerging concern, and how DFC affects B[a]P toxicity. Exposure to binary mixtures of these chemicals resulted in substantially reduced cytotoxicity in human HepG2 cells compared to single-chemical exposures.

Reactive oxygen species-dependent transient induction of genotoxicity by retene in human liver HepG2 cells.

Retene is a polycyclic aromatic hydrocarbon (PAH) emitted mainly by biomass combustion, and despite its ubiquity in atmospheric particulate matter (PM), studies concerning its potential hazard to human health are still incipient. In this study, the cytotoxicity and genotoxicity of retene were investigated in human HepG2 liver cells. Our data showed that retene had minimal effect on cell viability, but induced DNA strand breaks, micronuclei formation, and reactive oxygen species (ROS) formation in a dose- and time-dependent manner.

A yearlong monitoring campaign of polycyclic aromatic compounds and other air pollutants at three sites in Sweden: Source identification, in vitro toxicity and human health risk assessment.

Air pollution is a complex mixture of gases and particulate matter (PM) with local and non-local emission sources, resulting in spatiotemporal variability in concentrations and composition, and thus associated health risks. To study this in the greater Stockholm area, a yearlong monitoring campaign with in situ measurements of PM, PM, black carbon, NO, O, and PM-sampling was performed. The locations included an Urban and a Rural background site and a Highway site.

Determination of whole mixture-based potency factors for cancer risk assessment of complex environmental mixtures by in vitro testing of standard reference materials.

Whole mixture-based testing using in vitro new approach methodologies (NAMs) has been suggested to facilitate the hazard and risk assessment of complex environmental mixtures. Previous studies have shown that phosphorylation of DNA damage signaling proteins checkpoint kinase 1 (pChk1) and histone 2AX (γH2AX) are sensitive markers that can be used for estimating carcinogenicity potencies in vitro. Here, and with the aim to better validate the applicability, in vitro-based Mixture Potency Factors (MPFs) of Standard Reference Materials (SRMs) from environmental polycyclic aromatic hydrocarbon (PAH)-containing mixtures were determined and compared to published mutagenicity and tumorigenicity data.

Toll-like receptor inflammatory cascade and the development of diabetic kidney disease in children and adolescents with type 1 diabetes.

Aim: This study aimed to evaluate the association of toll-like receptor (TLR) inflammatory cascade with the development of diabetic kidney disease (DKD) in children and adolescents with type 1 diabetes (T1D).

Methods: A total of 49 T1D patients and 49 normoglycaemic (NG) subjects aged 5-20 years old were recruited. TLR2, TLR4, MYD88, NFKB, MCP1/CCL2 and IL18 mRNA expressions were measured in peripheral blood mononuclear cells by reverse transcription-quantitative polymerase chain reaction.

In vitro cytotoxicity and genotoxicity of single and combined pesticides used by Bolivian farmers.

We previously showed that farmers in Bolivia are exposed to many pesticides, some at elevated levels, and that this was associated with increased risk of genetic damage. To improve the understanding of possible mixture effects, the cytotoxicity and genotoxicity of pesticides were studied in vitro using human liver HepG2 cells. The studied pesticides were 2,4-D, chlorpyrifos, cypermethrin, glyphosate, methamidophos, paraquat, profenofos, and tebuconazole.

Polycyclic aromatic compounds in particulate matter and indoor dust at preschools in Stockholm, Sweden: Occurrence, sources and genotoxic potential in vitro.

Children spend a significant amount of their day in preschool; thus, environmental quality at preschools may have an impact on children's health. In the present study, we analyzed polycyclic aromatic compounds (PACs), including PAHs, alkylated PAHs and oxygenated PAHs (OPAHs), in indoor and outdoor air particulate matter (PM) and indoor dust at preschools in Stockholm, Sweden. There were significant correlations between PAC levels in outdoor and indoor PM, with in general higher PAC levels outdoors.

Buccal micronucleus cytome assay: Inter-laboratory scoring exercise and micronucleus and nuclear abnormalities frequencies in different populations from Brazil.

The Buccal Micronucleus Cytome Assay (BMCyt) has become an important biomonitoring tool for assessing cytogenetic damage in many studied populations. Each laboratory applies protocols that vary according to the method of collecting and preparing samples. Besides, Brazil is a country of great territorial extensions that received immigrants from various parts of the world with different genetic backgrounds.

Genotoxicity and DNA damage signaling in response to complex mixtures of PAHs in biomass burning particulate matter from cashew nut roasting.

Approximately 3 billion people world-wide are exposed to air pollution from biomass burning. Herein, particulate matter (PM) emitted from artisanal cashew nut roasting, an important economic activity worldwide, was investigated. This study focused on: i) chemical characterization of polycyclic aromatic hydrocarbons (PAHs) and oxygenated (oxy-) PAHs; ii) intracellular levels of reactive oxygen species (ROS); iii) genotoxic effects and time- and dose-dependent activation of DNA damage signaling, and iv) differential expression of genes involved in xenobiotic metabolism, inflammation, cell cycle arrest and DNA repair, using A549 lung cells.

Oxidative stress, mutagenic effects, and cell death induced by retene.

Retene (RET) is the most abundant polycyclic aromatic hydrocarbon (PAH) released upon burning of cellulose, although it is not considered as one of the priority PAHs and is not included for risk assessments by the US Environmental Protection Agency (US-EPA). There are only a few studies concerning the toxic effects of RET. To the best of our knowledge, this study is the first one to examine whether RET, in an environmental concentration, plays a crucial role in the induction of oxidative stress in A549 lung cell line, and its consequence as such as mutagenicity and cell death.

TREML4 mRNA Expression and Polymorphisms in Blood Leukocytes are Associated with Atherosclerotic Lesion Extension in Coronary Artery Disease.

Members of the triggering receptor expressed on myeloid cells (TREM) family are associated with atherosclerosis risk and progression. TREML4 is upregulated in the early phase of acute coronary syndrome. We investigated the relationship between the mRNA expression of 13 genes in blood leukocytes, TREML4 polymorphisms, and coronary artery lesion extension (Friesinger index) in patients with coronary artery disease (CAD) (n = 137).

Biomass burning particles in the Brazilian Amazon region: Mutagenic effects of nitro and oxy-PAHs and assessment of health risks.

Emissions from burning of biomass in the Amazon region have adverse effects on the environment and human health. Herein, particulate matter (PM) emitted from biomass burning in the Amazon region during two different periods, namely intense and moderate, was investigated. This study focused on: i) organic characterization of nitro- and oxy-polycyclic aromatic hydrocarbons (PAHs); ii) assessment of the excess lifetime cancer risk (LCR); and iii) assessment of the in vitro mutagenic effects of extractable organic matter (EOM).

Cell death pathways of particulate matter toxicity.

Humans are exposed to various complex mixtures of particulate matter (PM) from different sources. Long-term exposure to high levels of these particulates has been linked to a diverse range of respiratory and cardiovascular diseases that have resulted in hospital admission. The evaluation of the effects of PM exposure on the mechanisms related to cell death has been a challenge for many researchers.

Characterization of the particulate matter and relationship between buccal micronucleus and urinary 1-hydroxypyrene levels among cashew nut roasting workers.

The present study is the first assessment of occupational risk associated with artisanal cashew nut roasting using exposure and effect biomarkers, as well as a characterization and dispersion analysis of the released particulate matter (PM). A real-time particle monitor was used to quantify PM, PM and PM. Furthermore, the PM was sampled using a Handi-vol sampler, and the physicochemical characteristics were determined by SEM-EDS analysis.

Mutagenic potential assessment associated with human exposure to natural radioactivity.

Lucrécia city, known to harbor a high cancer rate, is located in a semiarid region characterized by the presence of mineral reservoirs, facing a high exposure to metal and natural radioactivity. The present study aimed to assess the environmental scenario at a semiarid region located in Northeastern Brazil. Metal concentration, alpha and beta radiation, and cyanobacteria content in tap water along with indoor radon and gamma emitters (U, K and Th) concentrations were measured.

Genetic damage of organic matter in the Brazilian Amazon: a comparative study between intense and moderate biomass burning.

Background: The biomass burning that occurs in the Amazon region has an adverse effect on environmental and human health. However, in this region, there are limited studies linking atmospheric pollution and genetic damage.

Objective: We conducted a comparative study during intense and moderate biomass burning periods focusing on the genetic damage and physicochemical analyses of the particulate matter (PM).