Environmental exposure to carcinogenic polycyclic aromatic hydrocarbons—The interpretation of cytogenetic analysis by FISH

Polycyclic Aromatic Hydrocarbons (PAHs) in Wildfire Smoke Accumulate on Indoor Materials and Create Postsmoke Event Exposure Pathways

Wildfire smoke contains PAHs that, after infiltrating indoors, accumulate on indoor materials through particle deposition and partitioning from air. We report the magnitude and persistence of select surface associated PAHs on three common indoor materials: glass, cotton, and mechanical air filter media. Materials were loaded with PAHs through both spiking with standards and exposure to a wildfire smoke proxy. Loaded materials were aged indoors over ∼4 months to determine PAH persistence. For materials spiked with standards, total PAH decay rates were 0.010 ± 0.002, 0.025 ± 0.005, and 0.051 ± 0.009 day-1, for mechanical air filter media, glass, and cotton, respectively. PAH decay on smoke-exposed samples is consistent with that predicated by decay constants from spiked materials. Decay curves of smoke loaded samples show that PAH surface concentrations are elevated above background for ∼40 days after the smoke clears. Cleaning processes efficiently remove PAHs, with reductions of 71% and 62% after cleaning smoke-exposed glass with ethanol and a commercial cleaner, respectively. Laundering smoke-exposed cotton in a washing machine and heated drying removed 48% of PAHs. An exposure assessment indicates that both inhalation and dermal PAH exposure pathways may be relevant following wildfire smoke events.

Effects of African BaP emission from wildfire biomass burning on regional and global environment and human health

The vegetation burning caused by wildfires can release significant quantities of aerosols and toxic chemicals into the atmosphere and result in health risk. Among these emitted pollutants, Benzo(a)pyrene (BaP), the most toxic congener of 16 parent PAHs (polycyclic aromatic hydrocarbons), has received widespread concerns because of its carcinogenicity to human health. Efforts have been made to investigate the environmental and health consequences of wildfire-induced BaP emissions in Africa. Still, uncertainties remain due to knowledge and data gaps in wildfire incidences and biomass burning emissions. Based on a newly-developed BaP emission inventory, the present study assesses quantitatively the BaP environment cycling in Africa and its effects on other continents from 2001 to 2014. The new inventory reveals the increasing contribution of BaP emission from African wildfires to the global total primarily from anthropogenic sources, accounting for 48% since the 2000 s. We identify significantly higher BaP emissions and concentrations across sub-Saharan Africa, where the annual averaged BaP concentrations were as high as 5-8 ng/m³. The modeled BaP concentrations were implemented to estimate the lifetime cancer risk (LCR) from the inhalation exposure to BaP concentrations. The results reveal that the LCR values in many African countries exceeded the acceptable risk level at 1 × 10^-6, some of which suffer from very high exposure risk with the LCR>1 × 10^-4. We show that the African BaP emission from wildfires contributed, to some extent, BaP contamination to Europe as well as other regions, depending on source proximity and atmospheric pathways under favorable atmospheric circulation patterns.

A study of the spatial distribution patterns of airborne polycyclic aromatic hydrocarbons in crowberry (Empetrum nigrum) in Ilulissat, Greenland

Polycyclic aromatic hydrocarbons (PAHs) are produced by anthropogenic activities, such as traffic and domestic heating. Due to their adverse effects to humans and natural habitats, the presence of PAHs in the environment needs to be monitored. Plants are known as natural accumulators of persistent organic pollutants (POPs) and can therefore be used for the monitoring of PAHs emitted into the environment. Contamination by PAHs also occurs in the Arctic such as Greenland due to long-range transport through air. However, as anthropogenic activities in the Arctic are increasing, there is a need to investigate the distribution of PAHs due to local emission sources. In this study, we present a systematic sampling approach to identify the influence of PAH sources in an area next to the town of Ilulissat in Greenland. Composite crowberry samples have been collected north of Ilulissat, where the town itself, an incineration site and Ilulissat airport are possible emission sources for PAHs. Matrix solid-phase extraction was used for the extraction of PAHs and the chemical analysis was performed by gas chromatography with mass spectrometry detection (GC-MS). In total, 18 out of 19 investigated PAHs could be detected in Empetrum nigrum in a concentration range of 0.69 to 93.01 μg/kg_{dry weight}. Higher concentrations for most of the targeted PAHs were found close to the suspected emission sources and also along the road connecting them. For pyrene, the correlation between the concentration and the distance from the emission sources could be modelled and visualized using a two-dimensional exponential variogram and ordinary kriging. The range in which the samples were spatially correlated was approximately 500 m. Our results show that local emission sources contribute to the spatial distribution patterns of PAHs. Monitoring of pollution by airborne PAHs is therefore needed even in areas far from major pollution sources such as Ilulissat, Greenland. E. nigrum showed to be a feasible species for biomonitoring of PAHs due to its large abundance in the sampling area and its widespread availability in the Artic region.

Cluster Analysis Evaluating PM2.5, Occupation Risk and Mode of Transportation as Surrogates for Air-pollution and the Impact on Lung Cancer Diagnosis and 1-Year Mortality

Objective:

Epidemiological studies have reported the close relationship between risk for lung cancers and air pollution in particular, for non-smoking related lung cancers. However, most studies used residential address as proxies which may not estimate accurately an individual’s air pollution exposure. Therefore, the aim of this study was to identify risk factors such as occupation and mode of transportation associated with lung cancer diagnosis and death.

Methods:

Subjects with lung cancer (n=514) were evaluated both by chart reviews for clinical data and interviews to determine residential address for ten years, main occupation and main mode of transportation. Annual particulate matter with diameter size less than 2.5 micrometre (PM2.5) concentration were calculated based on particulate matter with diameter size less than 10 micrometre (PM10) data recorded by Malaysian Department of Environment. Logistic regression analysis, cluster analysis and the Cox regression analysis were performed to the studied variables.

Results:

This study concurred with previous studies that lung adenocarcinoma were diagnosed in predominantly younger, female non-smokers compared to the other types of lung cancers. Lung adenocarcinoma subjects had annual PM2.5 that was almost twice higher than squamous cell carcinoma, small cell carcinoma and other histological subtypes (p=0.024). Independent of smoking, the κ -means cluster analysis revealed two clusters in which the high risk cluster involves occupation risk with air pollution of more than four hours per day, main transportation involving motorcycle and trucks and mean annual PM2.5 concentration of more than 30 based on residential address for more than ten years. The increased risk for the high-risk cluster was more than five times for the diagnosis of lung adenocarcinoma (OR=5.69, 95% CI=3.14-7.21, p<0.001). The hazard ratio for the high-risk cluster was 3.89 (95% CI=2.12-4.56, p=0.02) for lung adenocarcinoma mortality at 1 year.

Conclusion:

High-risk cluster including PM2.5, occupation risk and mode of transportation as surrogates for air-pollution exposure was identified and highly associated with lung adenocarcinoma diagnosis and 1-year mortality.

Urban environment and cancer in wildlife: available evidence and future research avenues

While it is generally known that the risk of several cancers in humans is higher in urban areas compared with rural areas, cancer is often deemed a problem of human societies with modern lifestyles. At the same time, more and more wild animals are affected by urbanization processes and are faced with the need to adapt or acclimate to urban conditions. These include, among other things, increased exposure to an assortment of pollutants (e.g. chemicals, light and noise), novel types of food and new infections. According to the abundant literature available for humans, all of these factors are associated with an increased probability of developing cancerous neoplasias; however, the link between the urban environment and cancer in wildlife has not been discussed in the scientific literature. Here, we describe the available evidence linking environmental changes resulting from urbanization to cancer-related physiological changes in wild animals. We identify the knowledge gaps in this field and suggest future research avenues, with the ultimate aim of understanding how our modern lifestyle affects cancer prevalence in urbanizing wild populations. In addition, we consider the possibilities of using urban wild animal populations as models to study the association between environmental factors and cancer epidemics in humans, as well as to understand the evolution of cancer and defence mechanisms against it.

Correlation Analysis of PM10 and the Incidence of Lung Cancer in Nanchang, China

Air pollution and lung cancer are closely related. In 2013, the World Health Organization listed outdoor air pollution as carcinogenic and regarded it as the most widespread carcinogen that humans are currently exposed to. Here, grey correlation and data envelopment analysis methods are used to determine the pollution factors causing lung cancer among residents in Nanchang, China, and identify population segments which are more susceptible to air pollution. This study shows that particulate matter with particle sizes below 10 micron (PM₁₀) is most closely related to the incidence of lung cancer among air pollution factors including annual mean concentrations of SO₂, NO₂, PM₁₀, annual haze days, and annual mean Air Pollution Index/Air Quality Index (API/AQI). Air pollution has a greater impact on urban inhabitants as compared to rural inhabitants. When gender differences are considered, women are more likely to develop lung cancer due to air pollution. Smokers are more likely to suffer from lung cancer. These results provide a reference for the government to formulate policies to reduce air pollutant emissions and strengthen anti-smoking measures.

Risk factors of Lung Cancer in nonsmoker

Generally, the cause of lung cancer is attributed to tobacco smoking. But many of the new lung cancer cases have been reported in nonsmokers. Apart from smoking; air pollution, environmental exposure, mutations, and single-nucleotide polymorphisms are known to be associated with lung cancer. Improper diet, alcohol consumption, marijuana smoking, estrogen, infections with human papillomavirus (HPV), HIV, and Epstein-Barr virus are suggested to be linked with lung cancer but clear evidences to ascertain their relation is not available. This article provides a comprehensive review of various risk factors and the underlying molecular mechanisms responsible for increasing the incidence of lung cancer. The pathologic, histologic, and genetic differences exist with lung cancer among smokers and nonsmokers. A better understanding of the risk factors, differences in pathology and molecular features of lung cancer in smokers and nonsmokers and the mode of action of various carcinogens will facilitate the prevention and management of lung cancer.

Systematic review of the use of the lymphocyte cytokinesis-block micronucleus assay to measure DNA damage induced by exposure to polycyclic aromatic hydrocarbons

The effect of exposure to polycyclic aromatic hydrocarbons (PAHs) to induce micronuclei (MN) measured using the lymphocytes cytokinesis-block micronucleus (CBMN) assay were evaluated in 34 studies according to the exposure: 20 studies in coke oven workers, 7 studies in different occupational exposures as alluminium industry workers, rubber factory workers, road construction workers, airport workers and diesel exposed workers, 6 studies on environmentaly exposed groups as police, volunteers and children. Reviewed papers indicate that the CBMN assay is a sensitive biomarker of PAHs exposure in polluted air. Reviewed studies confirmed previous conclusions, that the frequency of MN measured using the lymphocyte CBMN is not significantly affected by smoking, females are more sensitive to PAHs than males, the frequency of MN is increased with age.

Pollutional haze as a potential cause of lung cancer

Along with fast economic growth over the past few decades, the world is faced with cumulatively serious environmental pollution and now is paying increased attention to pollutional haze. In the last few years, multiple epidemiological studies and animal models have provided compelling evidences that inhalation of pollutional haze could be linked to several adverse health effects. Since the respiratory tract is the crucial passageway of entry of pollutional haze, the lung is the main affected organ. Therefore, here, we reviewed some of the important information around long-term exposure to pollutional haze and lung cancer, as well as highlight important roles of pollutional haze in human lung carcinogenesis, providing evidence for pollutional haze acting as another risk factor for lung cancer.

Causes of genome instability: the effect of low dose chemical exposures in modern society

Genome instability is a prerequisite for the development of cancer. It occurs when genome maintenance systems fail to safeguard the genome's integrity, whether as a consequence of inherited defects or induced via exposure to environmental agents (chemicals, biological agents and radiation). Thus, genome instability can be defined as an enhanced tendency for the genome to acquire mutations; ranging from changes to the nucleotide sequence to chromosomal gain, rearrangements or loss. This review raises the hypothesis that in addition to known human carcinogens, exposure to low dose of other chemicals present in our modern society could contribute to carcinogenesis by indirectly affecting genome stability. The selected chemicals with their mechanisms of action proposed to indirectly contribute to genome instability are: heavy metals (DNA repair, epigenetic modification, DNA damage signaling, telomere length), acrylamide (DNA repair, chromosome segregation), bisphenol A (epigenetic modification, DNA damage signaling, mitochondrial function, chromosome segregation), benomyl (chromosome segregation), quinones (epigenetic modification) and nano-sized particles (epigenetic pathways, mitochondrial function, chromosome segregation, telomere length). The purpose of this review is to describe the crucial aspects of genome instability, to outline the ways in which environmental chemicals can affect this cancer hallmark and to identify candidate chemicals for further study. The overall aim is to make scientists aware of the increasing need to unravel the underlying mechanisms via which chemicals at low doses can induce genome instability and thus promote carcinogenesis.

Impact of exposure to cooking fuels on stillbirths, perinatal, very early and late neonatal mortality - a multicenter prospective cohort study in rural communities in India, Pakistan, Kenya, Zambia and Guatemala

Background

Consequences of exposure to household air pollution (HAP) from biomass fuels used for cooking on neonatal deaths and stillbirths is poorly understood. In a large multi-country observational study, we examined whether exposure to HAP was associated with perinatal mortality (stillbirths from gestation week 20 and deaths through day 7 of life) as well as when the deaths occurred (macerated, non-macerated stillbirths, very early neonatal mortality (day 0–2) and later neonatal mortality (day 3–28).

Questions addressing household fuel use were asked at pregnancy, delivery, and neonatal follow-up visits in a prospective cohort study of pregnant women in rural communities in five low and lower middle income countries participating in the Global Network for Women and Children’s Health’s Maternal and Newborn Health Registry. The study was conducted between May 2011 and October 2012. Polluting fuels included kerosene, charcoal, coal, wood, straw, crop waste and dung. Clean fuels included electricity, liquefied petroleum gas (LPG), natural gas and biogas.

Results

We studied the outcomes of 65,912 singleton pregnancies, 18 % from households using clean fuels (59 % LPG) and 82 % from households using polluting fuels (86 % wood). Compared to households cooking with clean fuels, there was an increased risk of perinatal mortality among households using polluting fuels (adjusted relative risk (aRR) 1.44, 95 % confidence interval (CI) 1.30-1.61). Exposure to HAP increased the risk of having a macerated stillbirth (adjusted odds ratio (aOR) 1.66, 95%CI 1.23-2.25), non-macerated stillbirth (aOR 1.43, 95 % CI 1.15-1.85) and very early neonatal mortality (aOR 1.82, 95 % CI 1.47-2.22).

Conclusions

Perinatal mortality was associated with exposure to HAP from week 20 of pregnancy through at least day 2 of life. Since pregnancy losses before labor and delivery are difficult to track, the effect of exposure to polluting fuels on global perinatal mortality may have previously been underestimated.

Trial registration

ClinicalTrials.gov NCT01073475

Evaluation of chromosomal aberrations caused by air pollutants in some taxi drivers from two polluted districts of urban Tehran and its comparison with drivers from rural areas of Lahijan: a pilot study

BACKGROUND

Chromosome instability is the most common form of genomic instability. Genomic instability can lead to tumorogenesis. High level of chromosomal aberrations in peripheral blood lymphocytes can be used as a biomarker for cancer. Air pollution is one of the most important factors that cause chromosomal instability (CIN). In this comparative study we used classic Cytogenetic technique to analyze the effects of air pollutants on chromosome stability. We collected peripheral blood from 30 taxi drivers of two polluted districts (districts 6 and 7) in Tehran and 30 taxi drivers from rural areas of Lahijan, north of Iran.

RESULTS

Comparison of the level of chromosome breakage in the two groups showed an increased level of chromosome breakage in the drivers from polluted districts of Tehran, although not significant, using Fisher exact test (p-value = 0.300). However, the overall chromosome aberration rate (including both chromosome and chromatid gaps), the difference was significant using Chi-square test (p-value = 0.012).

CONCLUSION

An increased level of chromosome aberration was present in the drivers from polluted districts of Tehran compared to drivers from non-polluted areas in Lahijan.

The International Agency for Research on Cancer (IARC) evaluation of the carcinogenicity of outdoor air pollution: focus on China

The International Agency for Research on Cancer (IARC) has classified outdoor air pollution and the particulate matter (PM) in outdoor air pollution as carcinogenic to humans, as based on sufficient evidence of carcinogenicity in humans and experimental animals and strong support by mechanistic studies. The data with important contributions to the evaluation are reviewed, highlighting the data with particular relevance to China, and implications of the evaluation with respect to China are discussed. The air pollution levels in Chinese cities are among the highest observed in the world today and frequently exceed health-based national and international guidelines. Data from high-quality epidemiologic studies in Asia, Europe, and North America consistently show positive associations between lung cancer and PM exposure and other indicators of air pollution, which persist after adjustment for important lung cancer risk factors, such as tobacco smoking. Epidemiologic data from China are limited but nevertheless indicate an increased risk of lung cancer associated with several air pollutants. Excess cancer risk is also observed in experimental animals exposed to polluted outdoor air or extracted PM. The exposure of several species to outdoor air pollution is associated with markers of genetic damage that have been linked to increased cancer risk in humans. Numerous studies from China, especially genetic biomarker studies in exposed populations, support that the polluted air in China is genotoxic and carcinogenic to humans. The evaluation by IARC indicates both the need for further research into the cancer risks associated with exposure to air pollution in China and the urgent need to act to reduce exposure to the population.

The European Hot Spot of B[a]P and PM2.5 Exposure—The Ostrava Region, Czech Republic: Health Research Results

The Ostrava Region in the Czech Republic is a heavily polluted industrial area. Concentrations of PM10, PM2.5, and benzo[a]pyrene (B[a]P) significantly exceed limit values. To investigate the impact of these levels on human health, epidemiological, molecular epidemiology, and in vitro studies were done in 2008–2011. Morbidity of children was followed in 10 pediatric districts. In the most polluted district, children suffered higher incidence of acute respiratory diseases in the first year of life, and higher prevalence of asthma bronchiale. Gene expression was studied in children from Ostrava and from a control rural area. Genes specific to asthma bronchiale differed, suggesting a different molecular phenotype in children in the polluted region compared to children in the control area. A molecular epidemiology study showed adverse effect of the Ostrava exposures, but also an increased expression of XRCC5, which probably protects these exposed subjects against the degree of genetic damage that would otherwise be expected. In vitro studies clearly related concentration of B[a]P from PM2.5 extracts to induced PAH-DNA adducts. These studies clearly demonstrate that under the present local environmental conditions, the health of the population is severely impaired and will likely remain so for a significant period of time.

Biomarkers of exposure and effect-interpretation in human risk assessment

The effect of exposure to carcinogenic polycyclic aromatic hydrocarbons adsorbed onto respirable air particles (PM2.5, diameter < 2.5 μm) on DNA adducts and chromosomal aberrations was repeatedly studied in Prague, Czech Republic, in groups of policemen working in the downtown area and in bus drivers. Personal exposure was evaluated using personal samplers during working shifts. DNA adducts were analyzed in lymphocytes by the (32)P-postlabeling assay and chromosomal aberrations were analyzed by conventional cytogenetic analysis and fluorescent in situ hybridization (FISH). The impact of environmental pollution on DNA adducts and chromosomal aberrations was studied in a total of 950 subjects. Our results suggest that the environmental exposure of nonsmokers to concentrations higher than 1 ng benzo[a]pyrene/m(3) represents a risk of DNA damage, as indicated by an increase in DNA adducts and the genomic frequency of translocations determined by FISH.

Human biomonitoring in the Czech Republic: an overview

In the Czech Republic, the Human Biomonitoring Project (CZ-HBM) was launched in 1994 as an integral part of the nationwide Environmental Health Monitoring System (EHMS). Until now, the HBM covers two time periods: the first covered 1994-2003 and the second, 2005-2009. Altogether three population groups were included in the HBM: adults (blood donors aged 18-58 years), children aged 8-10 years, and breastfeeding primiparas. Sampling is organized on a yearly basis. Altogether three groups of biomarkers were analyzed: (a) selected heavy metals (Pb, Cd, Hg) and essential elements (Cu, Se, Zn) in blood and urine of adults and children, (b) indicator PCBs, DDT, DDE, HCB and HCHs in human milk and blood serum of adults and (c) cytogenetic changes in peripheral lymphocytes in blood of adults and children. This paper is focused on the general design of the CZ-HBM, the trends over time, and reference values. A significant downward time trend was observed for the blood lead levels in adults and children. Increased urinary cadmium levels were observed in Czech children compared to German children. The blood and urinary mercury levels were higher in women than in men. The levels of indicator PCB congeners in the Czech human milk samples were still higher than in most other European countries, because of existing hot spots. The levels of organochlorine pesticides showed a substantial continuous downward trend.

Micronuclei levels in mothers and their newborns from regions with different types of air pollution

The aim of this study was to analyze genetic damage in human lymphocytes measured using automated image analysis of micronuclei (MN) in a group of 178 mothers and their newborns from two locations in the Czech Republic. The concentrations of benzo[a]pyrene (B[a]P), particulate matter of aerodynamic diameter <2.5 μm (PM2.5) and benzene were measured by stationary monitoring in the winter season of 2008/2009 in the capital city of Prague and in Ceske Budejovice, a regional city in a rural area. The 3-month mean concentration of B[a]P before delivery was lower in Prague in comparison with Ceske Budejovice: 1.9 ± 0.5ng/m³ vs. 3.2 ± 0.2ng/m³ (p<0.001). The opposite trend was found for PM2.5 and benzene: 27.0 ± 2.5μg/m³ and 2.5 ± 0.5μg/m³ vs. 24.5 ± 0.7μg/m³ and 2.1 ± 0.8μg/m³ (p<0.001) for Prague vs. Ceske Budejovice, respectively. The average age of the mothers was 31 years (range, 18-49 years). The frequencies of MN per 1000 binucleated cells were 8.35 ± 3.06 vs. 6.47 ± 2.35 (p<0.001) for mothers from Prague and Ceske Budejovice, respectively, and 2.17 ± 1.32 vs. 3.82 ± 2.43 (p<0.001) for newborns from Prague and Ceske Budejovice, respectively. Other factors, including vitamin intake, exposure to tobacco smoke, body mass index (BMI) before pregnancy, the education level of the mothers and the impact of the mothers' and fathers' ages were analyzed in our study. The results suggest that the different sensitivity of the study groups to various mixtures of carcinogenic pollutants could be affected by significant differences in lifestyle factors. Possible higher genetic damage was analyzed in newborns of smoking mothers, and the birth weight of this group was 7.4% lower (p<0.05) in comparison with the newborns of nonsmoking mothers. No impact of the age of the mothers or fathers on MN frequency in the newborns was observed.

Expression of XRCC5 in peripheral blood lymphocytes is upregulated in subjects from a heavily polluted region in the Czech Republic

Air pollution causes oxidative damage to macromolecules, chromosomal aberrations and changes in gene expression. We investigated the levels of oxidative stress markers [8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), 15-F(2t)-isoprostane (15-F2t-IsoP), protein carbonyls] and cytogenetic parameters [genomic frequency of translocations (F(G)/100), percentage of aberrant cells (%AB.C.) and acentric fragments (ace)] in subjects living in Prague and in the heavily polluted Ostrava region. We also compared the expression of genes participating in base excision repair (BER) and non-homologous end-joining (NHEJ). We analyzed 64 subjects from Prague and 75 subjects from Ostrava. We measured oxidative stress markers by ELISA, cytogenetic parameters by fluorescence in situ hybridization and gene expression by quantitative PCR. The levels of air pollutants (benzo[a]pyrene, B[a]P; carcinogenic polycyclic aromatic hydrocarbons, c-PAHs; benzene) measured by personal monitors were significantly elevated in Ostrava compared to Prague (p<0.001). Despite this fact, we observed no differences in biomarkers of oxidative stress between the two locations. Moreover, subjects from Ostrava were less likely to have above-median levels of %AB.C. (OR; 95% CI: 0.18; 0.05-0.67; p=0.010). Multivariate analyses revealed that subjects living in Ostrava had increased odds of having above-median levels of XRCC5 expression (OR; 95% CI: 3.33; 1.03-10.8; q=0.046). Above-median levels of 8-oxodG were associated with decreased levels of vitamins C (OR; 95% CI: 0.37; 0.16-0.83; p=0.016) and E (OR; 95% CI: 0.25; 0.08-0.75; p=0.013), which were elevated in subjects from Ostrava. We suggest that air pollution by c-PAHs affects XRCC5 gene expression, which probably protects subjects from Ostrava against the induction of a higher frequency of translocations; elevated vitamin C and E levels in the Ostrava subjects decrease the levels of 8-oxodG.

Seasonal variations in the levels of PAH-DNA adducts in young adults living in Mexico City

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous components of polluted air. The Mexico City Metropolitan Area (MCMA), one of the most densely populated areas in the world, is 2240 m above sea level. At this altitude, less oxygen is available, making combustion less efficient and therefore producing more PAH pollutants. According to the Automatic Monitoring Network in Mexico City (RAMA, for its Spanish initials; http://www.sma.df.gob.mx/simat2/informaciontecnica/index.php?opcion=5&opciondifusion_bd=90), which performs environmental monitoring, the critical air pollutants in Mexico City are ozone and particulate matter (PM). PM emissions increase during the dry season (winter to spring) and decrease during the rainy season (summer to autumn). The bioactivation of some PAHs produces reactive metabolites that bind to DNA, and the presence of elevated levels of PAH-DNA adducts in tissues such as blood lymphocytes represents an elevated risk for the development of cancer. We have compared the levels of PAH-DNA adducts and the percentage of cells with chromosomal aberrations (CWAs) using a matched set of peripheral blood lymphocytes obtained on two separate occasions from young non-smoking inhabitants of the MCMA (n = 92) during the 2006 dry season and the following rainy season. PAH-DNA adducts were analysed using the r7, t8-dihydroxy-t-9, 10-oxy-7,8,9,10-tetrahydrobenzo[a]pyrene (BPDE)-DNA chemiluminescence immunoassay (CIA). The percentages of CWA were determined in cultured lymphocytes from the same individuals. Both DNA adduct levels and chromosomal aberrations were tested for correlation with lifestyle and the polymorphisms of cytochromes P450 CYP1A1 and CYP1B1 as well as glutathione-S-transferases GSTM1 and GSTT1. The levels of PAH-DNA adducts were significantly higher (P < 0.001) in the dry season (10.66 ± 3.05 per 10(9) nt, n = 92) than during the rainy season (9.50 ± 2.85 per 10(9) nt, n = 92) and correlated with the seasonal levels of particulate matter with a diameter of ≤ 10 μm (PM(10)). The percentage of CWA was not seasonally related; however, significant associations between the number of risk alleles and adduct levels in the dry (R = 0.298, P = 0.048) and in the wet seasons (R = 0.473, P = 0.001) were observed.

Effect of fungicide Euparen Multi (Tolylfluanid) on the induction of chromosomal aberations in cultivated bovine lymphocytes

The effect of the fungicide Euparen Multi (containing 50% tolylfluanid) was investigated on the induction of chromosomal aberrations (CA) in cultured bovine peripheral lymphocytes. Cultures from two healthy donors were treated with tolylfluanid-based fungicide at concentrations ranging from 1.7 to 17.5 μg/ml for the last 24 and 48 hours of cultivation. Conventional cytogenetic method (CA assay) with Giemsa staining as well as fluorescence in situ hybridization (FISH) with whole bovine chromosomes 1 and 5 painting probes were used in the experiment. In the CA assay, no clastogenic effect of the fungicide was found after Euparen Multi treatment for 24 hours. On the contrary, significant elevation in polyploidy induction was observed with dose-dependence in one of the donors. Using prolonged time of exposure to the fungicide (the last 48 h of the cultivation), a slight clastogenic effect was detected at the doses of 8.75 and 17.5 μg/ml (P < 0.05, P < 0.01, respectively) in donor 1 and at the dose of 8.75 μg/ml (P < 0.05) in donor 2. The highest doses tested caused reduction of the mitotic indices (MI) (P < 0.05, P < 0.01) in both donors as well as both treatment times. The evaluation of stable structural aberrations in lymphocytes by two-colour FISH (48 h exposure) using bovine chromosome painting probes revealed the presence of nonreciprocal translocations at two examined concentrations (3.5 μg/ml and 8.75 μg/ml).

Detection of trace anthracene in soil samples with real-time fluorescence quantitative immuno-PCR using a molecular beacon probe

We developed a highly sensitive and robust real-time fluorescence quantitative immuno-PCR (RTFQ-IPCR) method which uses molecular beacon (MB) probe to detect trace anthracene in the environment. This method was performed on serial dilutions of known anthracene concentrations equivalent to 10-fold dilutions of 10fg/mL to 100pg/mL. We obtained a linear relationship between 10fg/mL and 100pg/mL, with y=0.684x+13.221. A correlation coefficient of 0.994 was also identified, with a detection limit of 4.5fg/mL. After investigating the presence of anthracene in soil samples via RTFQ-IPCR, the obtained concentrations were confirmed by ELISA to be correct and believable, with the recovery ratio ranging from 82% to 112.5%. Based on its sensitivity and reproducibility, MB-based RTFQ-IPCR was found to be acceptable for use in on-site field tests to provide rapid, quantitative, and reliable test results for making environmental decisions.

The impact of air pollution on the levels of micronuclei measured by automated image analysis

The measurement of micronuclei (MN) in human peripheral blood lymphocytes is frequently used in molecular epidemiology as one of the preferred methods for assessing chromosomal damage resulting from environmental mutagen exposure. In the present study, we evaluated the effect of exposure to carcinogenic polycyclic aromatic hydrocarbons (c-PAHs), volatile organic compounds (VOC) and smoking on the frequency of MN in a group of 56 city policemen living and working in Prague. The average age of the participants was 34+/-6 years. The study was conducted on the same subjects in February and May 2007. The concentrations of air pollutants were obtained from personal and stationary monitoring. A statistically significant decrease in the levels of pollutants was observed in May when compared with February, with the exception of toluene levels measured by stationary monitoring. The frequency of MN was determined by the automatic image scoring (MetaSystems Metafer 4, version 3.2.1) of DAPI-stained slides. The results of the image analysis indicated a significant difference in the frequency of MN (mean levels 7.32+/-3.42 and 4.67+/-2.92, for February and May, respectively). Our study suggests that automatic image analysis of MN is a highly sensitive method for evaluating the effect of c-PAHs and confirms that there are no differences between smokers and nonsmokers. These results demonstrate the ability of c-PAHs to increase MN frequency, even if the exposure to c-PAHs occurred up to 60 days before the collection of biological material. Our work is the first human biomonitoring study focused on the measurement of MN by automated image analysis for assessing chromosomal damage as a result of environmental mutagen exposure.

Detection of naphthalene by real-time immuno-PCR using molecular beacon

A rapid and quantitative technique is urgently needed in detecting toxicological and carcinogenic polycyclic aromatic hydrocarbons (PAHs) in the environment. Using a molecular beacon (MB), this study aimed at detecting the presence of naphthalene through an assay developed via a highly sensitive and robust, real-time fluorescent quantitative immuno-PCR (FQ-IPCR), which was then performed on serial dilutions of known naphthalene concentrations equivalent to 10-fold dilutions of 1-10(4) fg/mL. A correlation coefficient of 0.996 was identified, and a linear relationship between 1 fg/mL and 10 pg/mL, with y = 1.392x + 11.188, was obtained. A trace amount (1 fg/mL) of naphthalene congeners could be detected using this method. Five water samples were then used for validation, the results of which were further confirmed through a conventional enzyme-linked immuno sorbent assay (ELISA). Based on sensitivity and reproduction, the MB-based FQ-IPCR technique is a promising tool for monitoring environmental endocrine disruptors.

Variation in particulate PAHs levels and their relation with the transboundary movement of the air masses

The levels of particulate polycyclic aromatic hydrocarbons (PAHs) were determined with a fast analytical approach to study their seasonal variations at Menen (Belgium) during 2003; they were found to be 5-7 times higher in January, February and December, in comparison to May, June and August. The annual average concentration of the sum of 16 US Environmental Protection Agency (EPA) criteria PAHs was 6.7 ng/m3 and around 63% of it was found to be probably carcinogenic to humans. The application of diagnostic ratio and principal component analysis showed vehicular emission as a major source. An increased ratio of 'combustion PAHs' to 'total EPA-PAHs' during the winter season indicated towards combustion activities. Further, the differences in PAHs concentration were assessed with relation to backward air mass trajectories, which show that the levels of PAHs increase when there is an air mass movement from Central and Western Europe and a fall when the trajectories spend most of their 4-day time over the Atlantic Ocean or in the Arctic region.