Objectives: Despite the quantum of research findings on tobacco epidemic, a review on the formation characteristics of nicotine, aldehydes and phenols, and their associated etiological risks is still limited in literature. Accordingly, knowledge on the chemical properties and free radical formation during tobacco burning is an important subject towards unravelling the relationship between smoking behaviour and disease. This review investigates how scientific efforts have been advanced towards understanding the release of molecular products from the thermal degradation of tobacco, and harm reduction strategies among cigarette smokers in general. The mechanistic characteristics of nicotine and selected aldehydes are critically examined in this review. For the purpose of this work, articles published during the period 2004-2021 and archived in PubMed, Google Scholar, Medley, Cochrane, and Web of Science were used. The articles were selected based on the health impacts of cigarette smoking, tobacco burning kinetics, tobacco cessation and tobacco as a precursor for emerging diseases such as Covid-19.
Content: The toxicity of cigarette smoke is directly correlated with its chemical composition derived from the pyrolysis of tobacco stem and leaves. Most of the harmful toxic substances are generated by pyrolysis during smoking and depends on pyrolysis conditions. Detailed studies have been conducted on the kinetics of nicotine by use of robust theoretical models in order to determine the rate constants of reactions in nicotine and those of nicotine dissociation via C-C and C-N scission, yielding pyridinyl and methyl radicals, respectively. Research has suggested that acetaldehyde enhances the effect of nicotine, which in turn reinforces addiction characteristics whereas acrolein and crotonaldehyde are ciliatoxic, and can inhibit lung clearance. On the other hand, phenol affects liver enzymes, lungs, kidneys, and the cardiovascular system while m-cresol attacks the nervous system.
Summary and outlook: The characteristics of chemical release during tobacco burning are very important in the tobacco industry and the cigarette smoking community. Understanding individual chemical formation from cigarette smoking will provide the necessary information needed to formulate sound tobacco reform policies from a chemical standpoint. Nonetheless, intense research is needed in this field in order to prescribe possible measures to deter cigarette smoking addiction and ameliorate the grave miseries bedevilling the tobacco smoking community.
Living beings have been devastated by environmental pollution, which has reached its peak. The disastrous pollution of the environment is in large part due to industrial wastes containing toxic pollutants. The widespread use of chromium (Cr (III)/Cr (VI)) in industries, especially tanneries, makes it one of the most dangerous environmental pollutants. Chromium pollution is widespread due to ineffective treatment methods. Bioremediation of chromium (Cr) using bacteria is very thoughtful due to its eco-friendly and cost-effective outcome. In order to counter chromium toxicity, bacteria have numerous mechanisms, such as the ability to absorb, reduce, efflux, or accumulate the metal. In this review article, we focused on chromium toxicity on human and environmental health as well as its bioremediation mechanism.
We reviewed published manuscripts from toxicology and epidemiology reporting harmful health effects and doses of persistent organic pollutants (POPs), published between 2000 and 2021. We found 42 in vitro, 32 in vivo, and 74 epidemiological studies and abstracted the dose associated with harm in a common Molar unit. We hypothesized that the dose associated with harm would vary between animal and human studies. To test this hypothesis, for each of several POPs, we assessed the significance of variation in the dose associated with a harmful effect [categorized as non-thyroid endocrine (NTE), developmental neurotoxicity (DNT), and Thyroid] with study type (in vitro, in vivo, and Epidemiology) using a linear model after adjustment for basis (lipid weight, wet weight). We created a Calculated Safety Factor (CSF) defined as the toxicology dose divided by epidemiology dose needed to exhibit significant harm. Significant differences were found between study types ranging from <1 to 5.0 orders of magnitude in the dose associated with harm. Our CSFs in lipid weight varied from 12.4 (95% confidence interval (CI) 3.3, 47) for NTE effects in Epidemiology relative to in vivo studies to 6,244 (95% CI 2510, 15530) for DNT effects in Epidemiology relative to in vitro in wet weight representing 12.4 to 6.2 thousand-fold more sensitivity in people relative to animals, and mechanistic models, respectively. In lipid weight, all CSF 95% CI lower bounds across effect categories were less than 6.5. CIs for CSFs ranged from less than one to four orders of magnitude for in vivo, and two to five orders of magnitude for in vitro vs. Epidemiology. A global CSF for all Epidemiology vs. all Toxicology was 104.6 (95% CI 72 to 152), significant at p<0.001.
A new health threat was appeared in 2019 known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or coronavirus disease 2019 (COVID-19). The new coronavirus distributed all over the world and caused millions of deaths. One way to incomplete the process of COVID-19 transfer from one person to another is using disinfectants. A narrative review study was done on manuscript published documents about the stability of the virus, different types of disinfectants and the effects of disinfectants on SARS-CoV2 and environment from 2005 to 2022 based on Searched databases included Google Scholar, Springer, PubMed, Web of Science and Science Direct (Scopus). All relevant studies published 2005 until 2022 gathered. According to the databases, 670 articles were retrieved. Thirty studies were screened after review and 30 full-text articles entered into the analysis process. Finally, 14 articles were selected in this study. New coronavirus could survive until 9 days in room temperature; the surviving time decreases if temperature increases. The virus can survive in various plastic, glass, and metal surfaces for hours to days. Disinfectants, such as alcohol, isopropanol, formaldehyde, glutaraldehyde, and ethanol, can kill 70-90% viruses in up to 30 s but should be noted that these disinfectants are recognized by Occupational Safety and Health Administration (OSHA) as a potential carcinogen. According to the different reports, increased duration and level of disinfectant exposure can have negative impacts on human and animal health including upper and lower respiratory tract irritation, inflammation, edema, ulceration, and allergic reactions.
The MOBI-Kids case-control study on wireless phone use and brain tumor risk in childhood and adolescence included the age group 10-24 years diagnosed between 2010 and 2015. Overall no increased risk was found although for brain tumors in the temporal region an increased risk was found in the age groups 10-14 and 20-24 years. Most odds ratios (ORs) in MOBI-Kids were <1.0, some statistically significant, suggestive of a preventive effect from RF radiation; however, this is in contrast to current knowledge about radiofrequency (RF) carcinogenesis. The MOBI-Kids results are not biologically plausible and indicate that the study was flawed due to methodological problems. For example, not all brain tumor cases were included since central localization was excluded. Instead, all brain tumor cases should have been included regardless of histopathology and anatomical localization. Only surgical controls with appendicitis were used instead of population-based controls from the same geographical area as for the cases. In fact, increased incidence of appendicitis has been postulated to be associated with RF radiation which makes selection of control group in MOBI-Kids questionable. Start of wireless phone use up to 10 years before diagnosis was in some analyses included in the unexposed group. Thus, any important results demonstrating late carcinogenesis, a promoter effect, have been omitted from analysis and may underestimate true risks. Linear trend was in some analyses statistically significant in the calculation of RF-specific energy and extremely low frequency (ELF)-induced current in the center of gravity of the tumor. Additional case-case analysis should have been performed. The data from this study should be reanalyzed using unconditional regression analysis adjusted for potential confounding factors to increase statistical power. Then all responding cases and controls could be included in the analyses. In sum, we believe the results as reported in this paper seem uninterpretable and should be dismissed.
As environmental and occupational noise can be health hazards, recent studies have investigated the effects of noise exposure during pregnancy. Despite biological plausibility and animal studies supporting an association, studies focusing on congenital anomalies and perinatal mortality as outcomes of noise exposure are still scarce. We performed a scoping review to collect, summarise, and discuss the existing scientific research about the relationships between noise exposure during pregnancy and congenital anomalies and/or perinatal mortality. We searched electronic databases for papers published between 1970 and March 2021. We included 16 studies (seven on congenital anomalies, three on perinatal mortality, and two on both congenital anomalies and perinatal mortality). We assessed four studies on congenital hearing dysfunction as the definition of congenital anomalies includes functional anomalies. We found few studies on this topic and no studies on the combined effects of occupational and environmental noise exposures. Evidence suggests a small increase in the risk of congenital anomalies in relation to occupational and to a lesser extent environmental noise exposure. In addition, few studies investigated perinatal mortality and the ones that did, used different outcome definitions, so no conclusions could be made. However, a recent big cross-sectional study demonstrated an association between road traffic noise and stillbirth. A few studies suggest a possible association between congenital hearing dysfunction and occupational noise exposure during pregnancy. Future studies with larger samples, better exposure assessments, and better statistical modelling strategies are needed to investigate these relationships further.
While Dieudonné has praised thoroughness of Leszczynski's review of EHS studies, he was critical of the final conclusions. Leszczynski strongly disagrees with argumentation of Dieudonné that EHS issue is settled and that biomarker research is unnecessary because it is expensive and might produce false positives. Leszczynski's opinion is that his review has demonstrated how very poor scientifically and inadequate statistically is the to-date executed research on EHS. Dieudonné's approach of using such poor science to justify claim that EHS issue is settled and there is no causality link between EHS and EMF exposures, is completely unjustified and simply false.