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PAHs are considered carcinogenic chemicals and are concerning as they are important organic pollutants in the environment and human society. The aim of the paper was to determine the levels of poly...

Vaping, or the use of electronic cigarettes, was initially introduced as a step toward smoking cessation, but has become an increasingly popular option for smokers. Though advertised as safer than conventional cigarettes, these devices have been found to contain carcinogenic chemicals, air pollutants, and heavy metals. The purpose of this article is to shed light on the known effects of vaping on the ocular setting and raise the discussion about additional potential effects that may call for further investigation. A comprehensive literature search was conducted for publications pertaining to the effects of vaping on the eye. Relevant studies and findings were summarized in this article. It was found that aldehydes and free radicals present in electronic cigarettes may induce a disturbance in tear film stability, and vape flavorings may damage the lipid layer through peroxidation. Corneal staining has been shown to appear following exposure to e-cigarette vapor, with nicotine and acrolein potentially inducing an inflammatory response in corneal epithelial cells. In addition, nicotine has been shown to induce nystagmus, exert vasoconstrictive effects on ocular blood flow, and may interfere with retinal light-adapted vision. Vape-related explosions, though unpredictable, may also result in decreased visual acuity along with long-term ocular trauma. Research discussing both the short-term and long-term effects of vaping on the eye is limited. However, the potential harms of substances such as nicotine and aldehydes warrant additional investigation and increased education about the detriment that electronic cigarettes may inflict on sensitive organs.

Plastic is a material that is used to a great extent. Nowadays Petroleum based plastics are widely used for the commercial purpose. This kind of plastics can take more than a century to degrade. Man made plastics have Polyurethane and Polyethylene polymers. It cannot be easily degraded by micro organisms as it don’t recognize as food. When burned plastics release cancer causing carcinogenic chemicals that are harmful to people and the environment. One eco friendly alternative the current commercial plastic is “Bio plastics”. Bio plastics are biodegradable plastics that have components derived directly from renewable raw plant materials. Seven type of bioplastics were made using various combinations of renewable raw materials and plasticizers. In this project, Cassava starch is used as a main biopolymer for the production of bio degradable bags.

The bacterial strains and mutagenicity test procedure developed by Bruce Ames, and published in 1973, greatly enhanced the ability of laboratories to test chemicals for mutagenicity. The test that became known as the "Ames Test" was simple to perform, took only two days, was relatively inexpensive, and was easily transferrable to other laboratories. Their demonstration that the test was effective at identifying potentially carcinogenic chemicals led its immediate adoption, and requirement, by regulatory authorities world-wide. Despite the development of other microbial and mammalian cell tests to measure mutation or other genetic damage, the Ames test still retains a primary role in the testing of chemicals for commercial use.

Introduction.Coal dust and coal fi ring products contain large amounts of carcinogenic chemicals (specifically benz[a]pyrene) that are different in influence on workers of coal mines and thermal power plants. Specific immune reactions to benz[a]pyrene therefore in these categories of workers can have specific features.Objective.To reveal features of antibodies specifi c to benz[a]pyrene formation in workers of coal mines and thermal power plants.Materials and methods.The study covered A and G class antibodies against benz[a]pyrene (IgA-Bp and IgG-Bp) in serum of 705 males: 213 donors of Kemerovo blood transfusion center (group 1, reference); 293 miners(group 2) and 199 thermal power plant workers (group 3). Benz[a]pyrene conjugate with bovine serum albumin as an adsorbed antigen was subjected to immune-enzyme assay.Results.IgA-Bp levels in the miners (Me = 2.7) did not differ from those in the reference group (Me = 2.9), but in the thermal power plant workers (Me = 3.7) were reliably higher than those in healthy men and in the miners (pConclusions.Specific immune reactions against benz[a]pyrene in the miners and the thermal power plant workers are characterized by peculiarities: the miners demonstrate lower levels of class A serum antibodies to benz[a]pyrene; the thermal power plant workers present increased serum levels of class G antibodies to benz[a]pyrene. These peculiarities result from only the occupational features, but do not depend on such factors as age, smoking and length of service at hazardous production. It is expedient to study specific immune reactions to benz[a]pyrene in workers of coal mines and thermal power plants, to evaluate individual oncologic risk and if malignancies occur.

Nanotechnology is considered one of the paramount forefronts in science over the last decade. Its versatile implementations and fast-growing demand have paved the way for innovative measures for the synthesis of higher quality nanomaterials. In the early stages, traditional synthesis methods were utilized, and they relied on both carcinogenic chemicals and high energy input for production of nano-sized material. The pollution produced as a result of traditional synthesis methods induces a need for environmentally safer synthesis methods. As the downfalls of climate change become more abundant, the scientific community is persistently seeking solutions to combat the devastation caused by toxic production methods. Green methods for nanomaterial synthesis apply natural biological systems to nanomaterial production. The present review highlights the history of nanoparticle synthesis, starting with traditional methods and progressing towards green methods. Green synthesis is a method just as effective, if not more so, than traditional synthesis; it provides a sustainable approach to nanomaterial manufacturing by using naturally sourced starting materials and relying on low energy processes. The recent use of active molecules in natural biological systems such as bacteria, yeast, algae and fungi report successful results in the synthesis of various nanoparticle systems. Thus, the integration of green synthesis in scientific research and mass production provides a potential solution to the limitations of traditional synthesis methods.

espanolContextualizacion: Una gran cantidad de productos quimicos deben ser utilizados en la industria y sectores tecnologicos, generado el incremento de enfermedades laborales asociada a factores como el tiempo de exposicion, la concentracion. Vacio de investigacion: El desconocimiento de la peligrosidad sumado a las condiciones de operacion de sustancias quimicas cancerigenas que se presentan en el ejercicio de las actividades diarias en la industria pueden afectar la salud Humana. Proposito: El objetivo del estudio es identificar y clasificar el riesgo relacionado con esas sustancias quimicas en una planta procesadora de alimentos carnicos en el departamento del Cauca (Colombia). Metodologia: En una primera fase de diagnostico se realizo una busqueda de informacion en bases de datos especializadas, en la segunda fase se desarrolla a partir de la informacion recolectada mediante el inventario de sustancias quimicas en la planta, que se encuentran distribuidas en diferentes sitios de almacenamiento con probabilidad de exposicion potencial. Para identificar la estimacion del riesgo quimico se aplico un analisis cualitativo mediante la utilizacion del criterio de caracterizacion de riesgos “caja de herramientas de control quimico internacional”. Posteriormente se hizo una revision de normatividad que rige en Colombia relacionada a la manipulacion, aplicativos y requisitos correspondientes de estas sustancias, estableciendo medidas de control y prevencion necesarias a la naturaleza quimica de estos agentes. Resultados obtenidos: Mediante el inventario se identificaron 407 sustancias presentes en la planta, de las cuales el 91% se clasifican dentro de sustancias quimicas peligrosas y un 3 % corresponde a sustancias quimicas con potencial efecto cancerigeno. Mediante la evaluacion de riesgo se tuvo en cuenta la combinacion de factores de peligro para la salud y exposicion potencial que determinan el nivel de control deseado, dividida en cuatro niveles de abordaje (1, 2, 3, 4) siendo el abordaje 4 de consideracion especial por ser el punto mas critico y de mayor peligrosidad. Conclusiones: Finalmente se determino que las sustancias de mayor atencion en la planta son: el cemento portland, DQO solucion B, Gasolina, Sikadur 32 Primer Comp B, Sikadur Panel Comp B, por estar dentro de abordaje 4. EnglishContextualization: A large number of chemical products are used in industry and technological sectors, generating health risks for those who are exposed, and may induce alterations depending on the concentration, manipulation, exposure, and susceptibility of the worker. These chemical agents can produce a variety of irritating allergic, toxic and even carcinogenic effects. Knowledeg gap: Ignorance of the danger added to the operating conditions of chemical carcinogenic chemicals that occur in the exercise of daily activities in the industry can affect human health. Purpose: The objective of the study is to identify and classify the risk related to these chemical substances in a meat food processing plant in the department of Cauca (Colombia). Methodology: In a first phase of diagnosis, an information search was carried out in specialized databases, in the second phase it was developed from the information collected through the inventory of chemical substances in the plant, which are distributed at different storage sites with potential exposure potential. To identify the chemical risk identification, a qualitative analysis is applied using the risk characterization criterion "international chemical control toolbox". Subsequently, a review of the regulations in force in Colombia related to the handling, applications and corresponding requirements of these substances was made, establishing necessary control and prevention measures for the chemical nature of these agents. Results and conclusions: Through the inventory, 407 substances present in the plant were identified, of which 91% are classified as dangerous chemicals and 3% correspond to chemicals with a potential carcinogenic effect. The risk assessment took into account the combination of risk factors for health and potential exposure that determines the level of control desired, divided into four levels of approach (1, 2, 3, 4), with approach 4 being considered Special for being the most critical and most dangerous point. Finally, it was determined that the substances of greatest attention in the plant are: portland cement, COD solution B, Gasoline, Sikadur 32 Primer Comp B, Sikadur Panel Comp B, for being within the approach 4.

The growing popularity of the cosmetics industry has made it vulnerable to duplication and counterfeiting. One in every five individuals purchases counterfeits cosmetics. Consumption of such cosmetics can be harmful to health. They might sometimes contain chemicals such as arsenic or other carcinogenic chemicals. The packagings of the counterfeit products are designed in such a manner that someone can barely differentiate it from the original one. The packaging of the duplicate products differs from that of the original in terms of certain features such as dimension, font style, font size, color, and ingredients. This paper reports the development of a system that uses the application of image processing and text extraction techniques that will enable a user to determine the authenticity of the test product. The system uses the features of the authentic product and compares them with the features of the test product to determine its authenticity. The system has been tested with some of the counterfeit and original cosmetic products.

Tobacco smoke is a complex mixture consisting of hundreds of toxic and carcinogenic chemicals, which may cause many diseases once inhaled. Among these toxic substances, radioactive and non-radioactive heavy metals present great health concerns to both active and passive smokers. However, conventional methodologies for characterizing heavy metals in smoke require intensive and time-consuming preparation procedures, and thus prevent their on-line applications. We report here a portable laser-induced breakdown spectroscopy (PLIBS) device for on-line detection of radioactive and non-radioactive heavy metals in tobacco smoke with ultra-high sensitivity. Two local cigarette brands were investigated, and a number of heavy metals were detected. In particular, several radioactive metals show very strong atomic emissions, and a limit of detection down to parts per trillion was obtained by single-shot PLIBS. The linear dependencies of their spectral intensities on the smoke concentrations were revealed, suggesting that the PLIBS is a promising tool for high-throughput and quantitative analysis of heavy metals in tobacco smoke. Tobacco emission dynamics were also investigated, and the results suggest the potential applications of the PLIBS in smoke risk assessment.

To better estimate cumulative cancer risks and avoid the overestimated risk from the linear extrapolation, an equivalency iterative algorithm associated with a carcinogenesis hypothesis was introduced for a mixture of chemicals with the same mode of action (MOA). A lognormal dose-response function was applied for carcinogenic chemicals. Under some circumstances, the repetitive random iterative algorithm could be transformed into the nonrepetitive one. It was also demonstrated that the equivalent value for a lognormal-based equivalency iterative algorithm with the same shape parameter was independent of the operation order. Based on the theorems of the algorithm and Plackett and Hewlett's minimum effective dose assumption, the sum of toxicity-weighted dose for a mixture of chemicals was mathematically derived. Compared to the estimation of risk by the linear extrapolation method (e.g., cancer slope factors), the equivalency iterative algorithm for lognormal functions can avoid overestimated risk significantly, which can help better estimate the cumulative cancer risk for a mixture of chemicals with the same MOA.

Cancer is one of the serious disease that causes several human deaths every year. Up to now, we have spent lots of time and money to investigate this disease, thereby designing effective treatments. Previous studies mainly focus on studying genetic background of different subtypes of cancer and neglect another important factor, environmental factor. Carcinogenic chemical is one of the type of environmental factor, exposure of such chemical may definitely initiate and promote the tumorigenesis. In this study, we tried to partly describe the differences between carcinogenic and non-carcinogenic chemicals using gene ontology (GO) terms and KEGG pathways. The carcinogenic and non-carcinogenic chemicals that were retrieved from Carcinogenic Potency Database (CPDB) were encoded into numeric vectors using the enrichment theories of GO terms and KEGG pathways. Then, the minimal redundancy maximal relevance (mRMR) method was adopted to analyze all features, resulting in some important GO terms and KEGG pathways. The extensive analysis of the identified GO terms and KEGG pathways indicate that they all play roles during the tumorigenesis, inducing that they can be key indicator for identification of carcinogenic chemicals.

This review presents a holistic overview of the occurrence, mobilization, and pathways of arsenic (As) from predominantly geogenic sources into different near-surface environmental compartments, together with the respective reported or potential impacts on human health in Latin America. The main sources and pathways of As pollution in this region include: (i) volcanism and geothermalism: (a) volcanic rocks, fluids (e.g., gases) and ash, including large-scale transport of the latter through different mechanisms, (b) geothermal fluids and their exploitation; (ii) natural lixiviation and accelerated mobilization from (mostly sulfidic) metal ore deposits by mining and related activities; (iii) coal deposits and their exploitation; (iv) hydrocarbon reservoirs and co-produced water during exploitation; (v) solute and sediment transport through rivers to the sea; (vi) atmospheric As (dust and aerosol); and (vii) As exposure through geophagy and involuntary ingestion. The two most important and well-recognized sources and mechanisms for As release into the Latin American population's environments are: (i) volcanism and geothermalism, and (ii) strongly accelerated As release from geogenic sources by mining and related activities. Several new analyses from As-endemic areas of Latin America emphasize that As-related mortality and morbidity continue to rise even after decadal efforts towards lowering As exposure. Several public health regulatory institutions have classified As and its compounds as carcinogenic chemicals, as As uptake can affect several organ systems, viz. dermal, gastrointestinal, peptic, neurological, respiratory, reproductive, following exposure. Accordingly, ingesting large amounts of As can damage the stomach, kidneys, liver, heart, and nervous system; and, in severe cases, may cause death. Moreover, breathing air with high As levels can cause lung damage, shortness of breath, chest pain, and cough. Further, As compounds, being corrosive, can also cause skin lesions or damage eyes, and long-term exposure to As can lead to cancer development in several organs.

The ranking of municipal formations of the Orenburg region on the incidence of malignant neoplasms of the colon, rectosigmoidal junction and rectum, and the level of carcinogens in food and drinking water has been ranked. Based on average concentrations, the total coefficients of carcinogens supplied with drinking water from centralized water supply and food products were calculated. Priority carcinogens have been identified in drinking water and food products that affect the occurrence of colon cancer, rectosigmoidal connective and rectum, as well as the risk area, with an increased incidence of colon cancer, rectosigmoid and rectal cancer caused by a carcinogenic load in drinking water and food Products.

Communicating with the public after corporate crises is often necessary, yet little evidence provides guidance. To address this, our theoretical and content analyses of public apologies revealed 12 key content elements. From these, we developed a basic apology, and tested its effectiveness alone, and with additional content. In two experiments involving river contamination, the basic apology was effective and improved with additional content. In Experiment 1, effectiveness involved actions taken to reduce harm and reoccurrence. Experiment 2 increased the hazard to carcinogenic chemicals, and one apology was superior: the basic apology plus statements of recovery efforts and defense of company actions. The two experiments show that crisis severity influences apology effectiveness. Experiment 3 found that clarifying causality helps convince people that the crisis source is identified and the problem resolved. Our findings show that an optimal public apology is comprehensive, and details the causes and actions taken to prevent reoccurrence.

Waste of electrical and electronic apparatuses generated in huge amount surround the earth today, and has become a global environmental issue. Electronic waste is a common, informal name for electronic products approaching the end of their useful life. The current and the future production of e-waste, the potential environmental problems associated with their disposal and management practices are discussed whereas the existing e-waste management. E-wastes are considered dangerous, as certain components of some electronic products contain materials that are harmful, depending on their condition and density. The harmful content of these materials pose a threat to human health and environment. Its toxic emissions mixed with virgin soil and air and causing harmful effects to the entire biota either directly or indirectly. Direct impacts include release of acids, toxic compounds including heavy metals, carcinogenic chemicals and indirect effects such as bio magnification of heavy metals. Discarded computers, televisions. DVD. stereos, copiers, fax machines, electric lamps, cell phones, audio equipment and batteries if improperly disposed can leach lead and other substances into soil and groundwater.

Society pays for her advances with an increasing amount of harmful potentially carcinogenic chemicals in the environment and at the workplace. The above is the second edition of a book first writte...

Large fires involving hazardous materials are often characterized by failing crisis communication. In this study, we compared opinions of experts regarding the risks of major fires to lay beliefs using a mental models approach. Amongst lay people this revealed relevant knowledge gaps and beliefs in opposition to those held by experts. While, experts considered the chance of getting cancer from inhaling smoke from a chemical fire extremely small, most lay people thought that even at a great distance, the chance of getting cancer to be large. To improve crisis communication about risk in a case of large chemical fires, and reduce the potential for messages to be misunderstood, distrusted or dismissed, we recommend a clarification of cancer risk in communications about public health emergencies such as chemical fires, for which lay people equate even small exposures to carcinogenic chemicals make one more likely to get cancer later in life.

Cancer is a significant health problem in the Middle East, and global population. It is well established that there is a direct link between tobacco smoking and cancer, which will continue to pose a significant threat to human health. The impact of long-term exposure to tobacco smoke on the risk of cancer encouraged the study of biomarkers for vulnerable individuals to tobacco smoking, especially children, who are more susceptible than adults to the action of environmental carcinogens. The carcinogens in tobacco smoke condensate induce DNA damage and play a significant role in determining the health and well-being of smokers, non-smoker, and primarily children. Cancer is a result of genomic and epigenomic malfunctions that lead to an initial premalignant condition. Although pre-malignancy genetic cascade is a much-delayed process, it will end with adverse health consequences. In addition to the DNA damage and mutations, tobacco smoke can cause changes in the DNA methylation and gene expression associated with cancer. The genetic events hint on the possible use of genomic-epigenomic changes in genes related to cancer, in predicting cancer risks associated with exposure to tobacco smoking. Bioinformatics provides indispensable tools to identify the cascade of expressed genes in active smokers and non-smokers and could assist the development of a framework to manage this cascade of events linked with the evolvement of disease including cancer. The aim of this minireview is to cognize the essential genomic processes and health risks associated with tobacco smoking and the implications of bioinformatics in cancer prediction, prevention, and intervention.

Human hair serves a biological purpose of protecting the scalp, as well as physical attractiveness to the perception of beauty. Hair loss, graying of hair, dandruff and other conditions affecting hair conditions can be distressing to patients, as hair condition is often considered important in people's own assessment of physical beauty. Different hair types can benefit from different treatment methods to promote hair health and growth. External factors like exposure to the sun and smoking, dietary factors including malnutrition of essential fatty acids and vitamins, and chemicals applied to the hair and scalp in shampoos and other treatments can all cause damage to existing hair and impair hair growth. Specific chemicals found in many shampoos, including antimicrobial agents, surfactants and preservatives, can all impair different aspects of hair health. In this review, we aim to discuss the main hair issues, such as hair loss, followed by the safety assessments of selected ingredients in shampoo, and possible nourishment for scalp improvement. This review highlights areas of disagreement in the existing literature, and points to new directions for future studies. Key conclusions include the carcinogenic chemicals to avoid, alternatives of such ingredients, and scalp nourishing treatments with micronutrients.

PAHs are mutagenic and carcinogenic chemicals formed during incomplete combustion of organic materials. They are metabolized to reactive metabolites that can damage DNA, resulting in cell death or mutations and cancer. Ovarian germ cells and follicles are highly sensitive to PAHs. Exposure to PAHs rapidly destroys germ cells in the developing ovary and primordial and primary follicles in the postnatal ovary. Ovarian cancers subsequently develop in these germ cell-depleted ovaries later in life. PAHs also cause death of granulosa cells of more mature secondary and antral follicles. This chapter discusses the mechanisms by which PAHs damage the ovary.

Several chemical hazards have been fount to be related to cured meat products. N-nitroso-compounds (NOCs) and polycyclic aromatic hydrocarbons (PAHs) were considered to increase the odds of colorectal cancer, as recently reviewed by the International Agency for Research on Cancer. This health concern involves products in which nitrites, nitrates, and smoking are used, but is especially linked to ready-to-eat meat products, namely dry-cured products (DCPs), where both of these risk factors are used simultaneously. Although the dry-curing process was a way to preserve meat products for a longer time, nowadays they earned their own status, being widely spread in gastronomy. Nitrite and smoking are used in DCP for safety and organoleptic purposes. The necessary reduction or elimination of nitrite and smoking in DCP must consider the control of significant foodborne pathogens, namely Clostridium botulinum, Staphylococcus aureus, Listeria monocytogenes, and Salmonella, and the sensory quality of DCP must meet the consumer’s acceptability criteria. This review aims to present strategies to reduce the use of nitrite and smoking in DCP, while assuring biological safety and maintaining the quality of these traditional products, namely through the use of natural ingredients, bacteriocins, edible active coatings, high hydrostatic pressure, and other emergent technologies.

Currently the use of synthetic mosquito repellent chemicals has several issues related to environment and human health. This project was formulated and developed to have safer mosquito repellent free from carcinogenic chemicals and are significantly cheaper and simple to develop. Dried powdered herbs like acorus, pyrethrum flower head, camphor, benzoin, neem leaves were used to make mosquito repellent formulation. The powdered blend were mixed with binders and additives like joss powder, charcoal powder. The solid formulation was rolled in the form of incense sticks. Further to add value, it was later scented with essential oil like lemongrass oil and dried. The incense sticks when ignited releases vapours with a pleasant fragrance and herbs which repels the mosquitoes. The incense sticks was tested for its potency by burning near the mosquito net cage with sufficient mosquitoes. The sticks also distributed to random peoples for feedback and were deemed to be very effective in controlling the mosquitos.

Evidence from studies in animals is essential for identifying chemicals likely to cause or contribute to many diseases in humans, including cancers. Yet, to avoid or delay the implementation of protective public health standards, the chemical industry typically denies cancer causation by agents they produce. The spurious arguments put forward to discount human relevance are often based on inadequately tested hypotheses or modes of action that fail to meet Bradford Hill criteria for causation. We term the industry attacks on the relevance of animal cancer findings as the "War on Carcinogens." Unfortunately, this tactic has been effective in preventing timely and appropriate health protective actions on many economically important yet carcinogenic chemicals, including: arsenic, asbestos, benzene, 1,3-butadiene, formaldehyde, methylene chloride, phthalates, tobacco usage, trichloroethylene [TCE], and others. Recent examples of the "War on Carcinogens" are chemicals causing kidney cancer in animals. Industry consultants argue that kidney tumor findings in rats with exacerbated chronic progressive nephropathy (CPN) are not relevant to humans exposed to these chemicals. We dispute and dismiss this unsubstantiated claim with data and facts, and divulge unprofessional actions from a leading toxicology journal.

Citation: Mario PS Chin (2013) Identification of Cigarette Smoke Condensate-Modulated Hiv-1-Associated Host Factors Using A Targeted Transcriptomic Approach. J HIV AIDS Infect Dis 1: 1-7. *Corresponding author: Mario PS Chin, Department of Microbiology and Immunology, Center for Substance Abuse Research, Temple University School of Medicine, 3440 N. Broad Street, Philadelphia; E-mail: mpschin@ temple.edu

Tobacco-specific nitrosamines (TSNAs) are carcinogenic chemicals found in tobacco plants. The increasing health consciousness of individuals had led to an increased interest in research on reducing TSNAs content. The aim of this study was to use a pot experiment in which exogenous substances were applied to burley tobacco to dissect the mechanism of TSNAs production. The results indicated that spraying the exogenous substances IAA, NAA, SA and combination thereof on burley tobacco after topping decreased TSNAs content by 2.69–29.4 % in upper leaves and 0.23–39.3 % in middle leaves without affecting total sugar, total nitrogen, potassium and chlorine contents. The application of exogenous substances could down-regulate expression of the NR gene and the activity of the NR enzyme, resulting in less accumulation of the TSNAs precursor nitrite. The exogenous substances significantly reduced nicotine accumulation, which was consistent with low enzyme activities and the down-regulated expressions of genes involved in nicotine biosynthesis, especially significant in the case of quinolinate phosphoribosyltransferase. These results suggested that the application of exogenous substances on burley tobacco after topping could reduce TSNAs content which may be attributed to the regulation of exogenous substances on nitrite and nicotine. This also implies one potential improvement to agronomic practices aimed at controlling the accumulation of TSNAs in burley tobacco.

The migration of gas from oil and gas fields to the surface is a problem that can greatly affect areas of urban development. Oilfields have demonstrated a long history of gas migration problems. Experience has shown that the migration of gas to the surface can create a serious potential risk of explosion, fires, noxious odors, and potential emissions of carcinogenic chemicals, such as BTEX. These risks must be seriously examined for any oil and/or gas operations in urban areas. Oilfield operations, however, can be conducted safely if proper precautions are taken.

Differences in cancer incidences between men and women are often explained by either differences in environmental exposures or by influences of sex hormones. However, there are few studies on intrinsic gender differences in susceptibility to chemical carcinogens. We have analyzed the National Toxicology Program (NTP) database for sex differences in rat responses to chemical carcinogens. We found that the odds that male rat bioassays were assigned a higher level of evidence than female rat bioassays was 1.69 ( p < .001). Of 278 carcinogenic chemicals in the database, 201 (72%) exhibited statistical gender differences ( p ≤ .05) in at least one nonreproductive organ. One hundred thirty of these 201 chemicals induced gender-specific tumors in male rats and 59 in female rats. Sixty-eight chemicals induced tumors in males but no tumors in females. Less than one third (i.e., 19 chemicals) induced tumors in females but not males. Male-specific tumors included pancreatic and skin tumors, and female-specific tumors included lung tumors. For some tumor sites, these differences in gender susceptibility can be associated with literature data on sex hormone receptor expression. In conclusion, gender-specific tumors were common. The male dominance is in line with recent human data, and the male susceptibility to carcinogens should be further studied.

This paper presents the work of an expert group established by the International Life Sciences Institute - European branch (ILSI Europe) to follow up the recommendations of an international conference on "Risk Assessment of Compounds that are both Genotoxic and Carcinogenic: New Approaches". Twelve genotoxic and carcinogenic chemicals that can be present in food were selected for calculation of a Margin of Exposure (MOE) between a point of departure on the dose-response for oral carcinogenicity in animal studies and estimates of human dietary exposure. The MOE can be used to support prioritisation of risk management action and, if the MOE is very large, on communication of a low level of human health concern. Depending on the approaches taken in determining the point of departure and the estimation of exposure, it is possible to derive very different values for the MOE. It is therefore essential that the selection of the cancer endpoint and mathematical treatment of the data are clearly described and justified if the results of the MOE approach are to be trusted and of value to risk managers. An outline framework for calculating an MOE is proposed in order to help to ensure transparency in the results.

The Ito Liver Model and the Ito Multi-organ Model are used in conjunction and constitute an efficient and rapid bioassay for the identification of both genotoxic and nongenotoxic carcinogenic chemicals. The Ito Liver Model is an 8-week bioassay system that uses the number and size of foci of hepatocytes positive for glutathione S-transferase placental form (GST-P) as the end-point marker. One hundred fifty-nine compounds were tested using the Ito Liver Model: 61 of 66 hepatocarcinogens tested positive, and 10 of 43 nonliver carcinogens were also positive. The false-positive detection of noncarcinogens was low; a single false-positive result was obtained from the 50 noncarcinogens tested. Since more than half of all known carcinogens are hepatocarcinogens in rodents, the initial 8-week bioassay is able to detect most carcinogens. The Ito Multi-organ Model is a 28-week bioassay system for the detection of carcinogens that were not identified by the Ito Liver Model. Results are evaluated by preneoplastic and neoplastic lesions in major organs. Forty-four compounds were tested using the Ito Multi-organ Model: 17 out of 17 liver carcinogens were positive, and 19 out of 22 (86%) nonliver carcinogens were positive. None of the five noncarcinogens tested positive.

This review covers chemical carcinogenesis studies in nonhuman primates performed by the National Cancer Institute, USA, to provide hitherto unavailable information on their susceptibility to compounds producing carcinogenic effects in rodents. From autopsy records of 401 breeders and untreated controls, incidences of spontaneous malignant tumors were found to be relatively low in cynomolgus (1.9%) and rhesus monkeys (3.8%), but higher in African green monkeys (8%). Various chemical compounds, and in particular 6 antineoplastic agents, 13 food-related compounds including additives and contaminants, 1 pesticide, 5 N-nitroso compounds, 3 heterocyclic amines, and 7 "classical" rodent carcinogens, were tested during the 34 years period, generally at doses 10 approximately 40 times the estimated human exposure. Results were inconclusive in many cases but unequivocal carcinogenicity was demonstrated for IQ, procarbazine, methylnitrosourea and diethylnitrosamine. Furthermore, negative findings for saccharine and cyclamate were in line with results in other species. Thus susceptibility to carcinogens is at least partly shared by nonhuman primates and rodents.

We developed and implemented a national surveillance system to monitor and reduce the levels of toxic chemicals in tobacco smoke. A developmental Healthy People 2010 (HP 2010) objective was revised to report on levels of three categories of chemicals—tobacco-specific nitrosamines, polyaromatic hydrocarbons, and volatile organic compounds—in the smoke of leading U.S. cigarette brands. Unit-based sales-weighted average levels were calculated for each chemical category. The target for the new HP 2010 objective is a 10% reduction in unit-based sales-weighted average levels of each chemical category. The Centers for Disease Control and Prevention provided the baseline, target data, and laboratory analyses. A national data source, national baseline data, and target were presented to the Healthy People Steering Committee during 2005 Midcourse Review. Approval of the revised objective initiated the surveillance of three major classes of toxic chemicals in cigarette smoke. The approved objective provides a feasible, innovative approach for monitoring and supporting measurable population-based reductions in levels of toxic and carcinogenic chemicals in tobacco smoke.

Art materials are used by individuals of all ages, ranging from kindergarten children to adults studying the arts at a university level, as well as the general public, senior citizens, and mentally compromised individuals. Art materials have the potential of containing toxic materials, including carcinogens (such as nickel, chromium, cadmium, and lead) and reproductive toxins in their formulations. These toxic chemicals can be present as a result of intentional addition or contaminants. Such occurrences are expected to be higher in products manufactured in countries where product safety laws are less strict or not properly enforced. Exposure to carcinogenic chemicals causes DNA damage leading to mutations that can activate oncogenes or inactivate antioncogenes, thus, predisposing cells to oncogenesis. Importantly, the heavy metals, such as nickel, can also dysregulate homologous DNA recombination (HR) (1). Although HR in normal cells is the most precise DNA repair mechanism and plays a vital role in the maintenance of genomic integrity, its dysregulation can induce genomic instability (2, 3), which is associated with progression in cancer (2). Data from our laboratory also show that exposure to nickel is associated with induction of a panel of HR genes, including (RAD51, RAD51 paralogs, RAD50, and RAD23) as well as leads to increased HR activity, genomic instability, and development of drug resistance in cancer (myeloma) cells (2). Toxic metals (such as nickel, copper, mercury, and lead) also induce breaks in DNA. Exposure to such chemicals even at low doses can be risky because their genotoxic effect can potentially be increased by their interactions with each other and/or with other environmental or genetic factors. It has been demonstrated that simultaneous exposure to more than one heavy metals is associated with increased toxicity, relative to that observed following exposure to single metal (4). Toxicity of these compounds can also be increased in the presence of X-rays. A model proposed by Hengstler et al. (5) suggests that simultaneous exposure to multiple metals can lead to several fold increase in the toxicity relative to that induced by single compound. We, therefore, believe that constant exposure to material containing such chemicals can potentially increase cancer risk, especially in the individuals with genetic and/or other susceptibilities, including those related to certain lifestyles (6). Consistently, the reports suggest that there is an increased incidence of death due to cancers of various organs in artists (7, 8). Art Materials that do contain toxic materials can have serious adverse health effects among users, especially small children and those with mental health issues. To minimize such effects, the US Government has enacted certain product safety laws and regulations. One of those regulations is the Federal Hazardous Substances Act (FHSA), which is being implemented by the US Consumer Product Safety Commission (CPSC). One of the components of the FHSA is “Labeling of Hazardous Art Materials Act (LHAMA).” This section deals with toxicological reviews of Art Material formulations for chronic toxicity and proper labeling. Labeling of Hazardous Art Materials Act requires that all art materials offered for sale to consumers of all ages in the US must undergo a toxicological review by a qualified toxicologist such as Diplomate American Board of Toxicology (DABT) of the complete formulation of each product to determine the product’s potential for producing adverse chronic health effects; in addition, the art materials be properly labeled for acute and chronic hazards, as required by the LHAMA (9) and the FHSA (10), respectively. An “art material” or “art material product” means any substance marketed or represented by the producer or repackager as suitable for use in any phase of the creation of any work of visual or graphic art of any medium and packaged in sizes intended for individual users of any age or those participating in a small group (11). After toxicological reviews have been conducted for chronic hazards on art material formulations, the qualified toxicologists then recommend appropriate statements for art materials and also recommend a conformance statement. The conformance statement can read: “Conforms to ASTM Practice D-4236”; “Conforms to ASTM D-4236”; or “Conforms to the health requirements of ASTM D-4236.” According to the regulation at 16 C.F.R. § 1500.14(b) (8) (i) (C) (6), these toxicological reviews are valid for the period of 5 years only. The regulation states: “[T]he producer or repackager shall have a toxicologist review as necessary, but at least every 5 years, art material product formulation(s) and associated label(s) based upon the then-current, generally accepted, well-established scientific knowledge.” Based on our long-term experience in the field, we have come to realize that it is impossible for the consumers to fully benefit from the 5-year re-review requirement; this is because either most consumers are unaware of 5-year re-reviewing requirement or they have no practical means to verify that the 5-year expiry period has already expired. Verification is only possible when the expiry date of the toxicological review or the date of toxicological review is marked on the Art Material label. This practice is also expected to help CPSC inspector assure compliance to 5-year re-review requirement. In the absence of expiry dates of the toxicological reviews, it is impossible for consumers to know if the art materials they buy and use are still in compliance with the Federal regulation and are in fact safe based on the current generally accepted, well-established scientific knowledge. Therefore, we suggest that the CPSC amends the LHAMA and incorporates the requirement of adding the dates toxicological reviews are conducted or the dates toxicological reviews will expire. This amendment will be in line with Section 103 of the CPSIA entitled “Tracking Labels for Children’s Products” (12) and Tracking Label Requirement for Children’s Products (12) that mandate, in pertinent part, “distinguishing marks” on all children’s products and their packaging to enable the manufacturer and the ultimate purchaser to “ascertain” certain source and production information. These markings are to enable the manufacturer, retailers, and the ultimate consumer to ascertain the manufacturer or private labeler, location and date of production of the product, and cohort information (batch, run number, or other identifying characteristic). These new requirements become effective on August 14, 2009. We believe that this practice will not only remove hundreds of non-compliant Art Materials out of the US market especially those imported from other countries, but will also protect US consumers, especially children, mentally compromised individuals, and the elderly from unchecked chronically toxic chemicals, including carcinogens and reproductive toxins.

Thresholds of exposures to genotoxic agents have been discussed for a long time, and experimental demonstrations of this could result in the establishment of acceptable daily intakes for managing risks associated with genotoxic carcinogens. Virtually safe doses (VSDs) and thresholds of toxicological concern (TTC) have also been used to ensure sufficiently low concentrations of carcinogenic chemicals. Accordingly, the ICH-M7 guideline Assessment and Control of DNA-Reactive (Mutagenic) Impurities in Pharmaceuticals to Limit Potential Carcinogenic Risk, finalized in Jun. 2014, highlights various assessments of genotoxic and mutagenic hazards to reduce the potential lifetime cancer risk from genotoxic impurities during clinical development and after approval of pharmaceutical agents. In this chapter, the concepts of VSD and TTC for managing risk associated with genotoxic carcinogens contained in pharmaceutical agents are reviewed.

Cancer is one of the leading causes of human death. Based on current knowledge, one of the causes of cancer is exposure to toxic chemical compounds, including radioactive compounds, dioxin, and arsenic. The identification of new carcinogenic chemicals may warn us of potential danger and help to identify new ways to prevent cancer. In this study, a computational method was proposed to identify potential carcinogenic chemicals, as well as non-carcinogenic chemicals. According to the current validated carcinogenic and non-carcinogenic chemicals from the CPDB (Carcinogenic Potency Database), the candidate chemicals were searched in a weighted chemical network constructed according to chemical–chemical interactions. Then, the obtained candidate chemicals were further selected by a randomization test and information on chemical interactions and structures. The analyses identified several candidate carcinogenic chemicals, while those candidates identified as non-carcinogenic were supported by a literature search. In addition, several candidate carcinogenic/non-carcinogenic chemicals exhibit structural dissimilarity with validated carcinogenic/non-carcinogenic chemicals.

The biological effects of low doses of toxic and carcinogenic chemicals are currently a matter of significant scientific controversy. This paper argues that philosophers of science can contribute to alleviating this controversy by examining it with the aid of a novel account of scientific anomaly. Specifically, analysis of contemporary research on chemical hormesis (i.e., alleged beneficial biological effects produced by low doses of substances that are harmful at higher doses) suggests that scientists may initially describe anomalous phenomena in terms of multiple distinct “characterizations,” each of which is compatible with current empirical evidence. By focusing attention on this feature of scientific anomalies, philosophers of science can alleviate the controversy over low-dose chemical effects in at least two ways: (1) they can pinpoint the significant ways in which particular characterizations frame the controversy, and (2) they can identify the methodological value judgments at stake in researchers’ choice of characterizations.

This paper summarizes the evidence on the Structural Alerts of mutagenicity and carcinogenicity. The Structural Alerts are molecular substructures or reactive groups that are related to the carcinogenic and mutagenic properties of the chemicals, and represent a sort of "codification" of a long series of studies aimed at highlighting the mechanisms of action of the mutagenic and carcinogenic chemicals. The identification of the Structural Alerts has had a great value both in terms of understanding mechanisms, and of assessing the risk posed by chemicals. This mini-review illustrates a number of case studies where the Structural Alerts have played a fundamental role in risk assessment, and describes recent work aimed at expanding or refining the knowledge on the Structural Alerts through the use of Artificial Intelligence and Data Mining approaches. As a matter of fact, the 1980's were the years during which the Quantitative Structure-Activity Relationships (QSAR) approach was having a dramatic development, with an exponential increase in methods and computerized technologies proposed, and the more qualitative approach based on the simple recognition of toxicophores was entering into shade. This is even more so today. However, the knowledge of the toxicophores, as recognition and classification of the molecular substructures and reactive groups responsible for the toxic effects, is still at the basis of the mechanistic science of toxicology and provides powerful means of intervention to "domesticate" the

Some polycyclic aromatic hydrocarbons (PAHs), particularly those with a high molecular mass, have been classified as probably being carcinogenic to humans by the International Agency for Research on Cancer (IARC). The significance of the determination of PAHs is reflected by the special attention the European Union is paying to regulating their maximum allowed levels in various types of foodstuffs. Like tobacco and smoked meats, alcoholic drinks can also contain these carcinogenic chemicals, as the latter have been detected in the charred insides of barrels, some ingredients such as caramel or the smoke released during the drying of germinated barley in beer or whisky. This paper determined the contents of seven PAHs in alcoholic beverages of variable alcoholic strength that had been aged in charred barrels for different times (months, years). The aim was to elucidate the dependence of the formation of seven PAHs on the type of charring (traditional or convective) used and the charring intensity (light, medium or heavy). Based on the results, the way the tree raw material is toasted strongly influences PAH levels in alcoholic drinks; thus, traditional charring produces increased amounts of PAHs from the wood relative to convective toasting. The sum of the analysed PAH concentrations in the aged alcoholic beverages studied ranged from zero for a white wine to 172 ng l(-1) for a 'brandy de jerez solera'. The carcinogenic indicator benzo[a]pyrene was found at concentrations below 10 ng l(-1). These PAH concentrations in alcoholic beverages are very low relative to those in smoked and char-broiled foodstuffs. Any health hazards, however, can be minimized by using convective toasting to manufacture the barrels where the drinks are to be aged.

A recent court decision denying injured migrant farm workers health care after their work visas expire is only the latest attack on these workers’ health rights, according to advocates, who say these labourers die, are injured or are exposed to carcinogenic chemicals with impunity in Canada. In