Induction of chromosome aberrations and micronuclei in pulmonary alveolar macrophages of rats following inhalation of mosquito coil smoke

Maternal Smoking in Pregnancy and Child's Hospital Use up to 5 Years of Age in a Data Linkage Birth Cohort

OBJECTIVES

To examine if exposure to maternal smoking during pregnancy is associated with emergency department (ED) presentation and admission through the ED in children up to 5 years after birth.

METHODS

Antenatal records of all children up to 5 years of age who were born in Tasmania, Australia, between July 2008 and June 2014 were linked to health service use (ED presentations and hospital admissions). Negative binomial regression was used to estimate the incidence rate ratio (IRR) and 95% confidence intervals (CIs) at ≤1 year and ≤5 years for ED presentations and admissions to the hospital through the ED for any reason and by 9 major disease categories for children exposed versus children not exposed to maternal smoking during pregnancy. Models were adjusted for sex, socioeconomic position, maternal age at birth, and region of residence. Presentations and admissions for poisoning and injuries were used as a negative control.

RESULTS

Among 36 630 infants, 21% were exposed to maternal smoking during pregnancy. Exposed children had a 26% higher rate of presentation to the ED (IRR_adjusted 1.26; 95% CI 1.23-1.29) and a 45% higher rate of admission (IRR_adjusted 1.45; 95% CI 1.39-1.51) at up to 5 years of age. Compared with the negative control, higher presentation and admission rates were evident in respiratory; eyes, ears, nose, and throat; psychosocial; and infectious disease categories.

CONCLUSIONS

Higher health care service use was observed in children exposed to maternal smoking during pregnancy for a range of conditions associated with exposure to smoking. The findings reinforce the need to reduce smoking among people in their childbearing years.

Comparative study of subchronic toxicities of mosquito repellents (coils, mats and liquids) on vital organs in Swiss albino mice

The aim of the current study was to evaluate and compare the toxicities of different types of mosquito repellents i.e. coils, mats and liquid vapors in animal models. Different types of mosquito repellents including liquid vaporizers, coils and mats have been extensively used by the people to get protection from the mosquitoes and diseases associated with them. The active constituents of these repellents include; allethrins, pyrethrins, paraffin and various other derivatives, are well known for their toxicities. Exposure of albino mice to these repellents for 3 h per day over a period of 20 days produced significant toxicological effects on vital body organs including; liver, lungs, kidneys, brain and heart. The order of toxicity of different repellents on nervous and hepatic tissues was found to be: Coil > Liquid > Mat while in renal and cardiac tissues, the coil was again found to be the most toxic one, mat with medium toxicity whereas liquid as least toxic (Coil > Mat > liquid). Lungs tissues are almost equally affected by all the repellants. On the basis of current findings, it has been concluded that exposure to various types of mosquito repellents can be deleterious to health and can cause various health related issues by producing pathological changes in the vital organs.

Biochemical and histological alterations induced by the smoke of allethrin based mosquito coil on mice model

BACKGROUND

Mosquito coil (MC) emits insecticide upon burning which provides limited protection against lethal mosquito borne diseases. However, apart from killing the insect, toxicities associated with the inhalation of these insecticides poses severe health hazards. However, the use of MC is increasing day by day in third world countries in particular but, yet to receive enough attention of both policy maker and general public. The current study was aimed to assess the MC smoke induced damage of pulmonary and hepatic tissues along with observing the alterations of several blood biochemical parameters in mice model.

METHODS

A total of twenty four Swiss albino mice were allowed to inhale the smoke of allethrin based MC at different duration per day for 120 days. By the end of treatment period, blood sample was drawn from each mouse and blood biochemical parameters including alanine transaminase (ALT), aspartate transaminase (AST), blood urea nitrogen(BUN), serum total protein, cholesterol, low density lipoprotein (LDL) and triglyceride (TG) were analyzed. Intact lung and liver were collected for histological analysis using standard protocol.

RESULTS

Biochemical study indicates elevated activity of two hepatic enzymes: ALT (89%), AST (85%), in comparison with the respective control. Increased level of some parameters of lipid profile including cholesterol (36%), LDL (48%) and triglyceride (30%) in smoke inhaled mice is the new finding of this study. On the contrary, the activity of serum total protein and BUN was decreased by 20% and 24%, respectively in inhaled mice. Pulmonary tissue of treated mice shows severe forms of emphysema and hyperplasia, especially in the peripheral region of lung, which is the hallmark of chronic obstructive pulmonary disease (COPD). Histological study of hepatic tissue shows apoptosis mediated damage of hepatocytes along with severe form of necrosis. Infiltration of Inflammatory cells was also observed in both of the organs.

CONCLUSION

Results from the present studies suggest that chronic exposure of allethrin based MC is responsible factor for severe health complications such as COPD due to the alterations of the key biochemical parameters of blood and histo-organization of lung and liver.

Acrylamide genotoxicity in young versus adult gpt delta male rats

The recent discovery that the potent carcinogen acrylamide (AA) is present in a variety of fried and baked foods raises health concerns, particularly for children, because AA is relatively high in child-favoured foods such as potato chips and French fries. To compare the susceptibility to AA-induced genotoxicity of young versus adult animals, we treated 3- and 11-week-old male gpt delta transgenic F344 rats with 0, 20, 40 or 80 p.p.m. AA via drinking water for 4 weeks and then examined genotoxicity in the bone marrow, liver and testis. We also analysed the level of N7-(2-carbamoyl-2-hydroxyethyl)-guanine (N7-GA-Gua), the major DNA adduct induced by AA, in the liver, testis and mammary gland. At 40 and 80 p.p.m., both age groups yield similar results in the comet assay in liver; but at 80 p.p.m., the bone marrow micronucleus frequency and the gpt-mutant frequency in testis increased significantly only in the young rats, and N7-GA-Gua adducts in the testis was significantly higher in the young rats. These results imply that young rats are more susceptible than adult rats to AA-induced testicular genotoxicity.

A core in vitro genotoxicity battery comprising the Ames test plus the in vitro micronucleus test is sufficient to detect rodent carcinogens and in vivo genotoxins

In vitro genotoxicity testing needs to include tests in both bacterial and mammalian cells, and be able to detect gene mutations, chromosomal damage and aneuploidy. This may be achieved by a combination of the Ames test (detects gene mutations) and the in vitro micronucleus test (MNvit), since the latter detects both chromosomal aberrations and aneuploidy. In this paper we therefore present an analysis of an existing database of rodent carcinogens and a new database of in vivo genotoxins in terms of the in vitro genotoxicity tests needed to detect their in vivo activity. Published in vitro data from at least one test system (most were from the Ames test) were available for 557 carcinogens and 405 in vivo genotoxins. Because there are fewer publications on the MNvit than for other mammalian cell tests, and because the concordance between the MNvit and the in vitro chromosomal aberration (CAvit) test is so high for clastogenic activity, positive results in the CAvit test were taken as indicative of a positive result in the MNvit where there were no, or only inadequate data for the latter. Also, because Hprt and Tk loci both detect gene-mutation activity, a positive Hprt test was taken as indicative of a mouse-lymphoma Tk assay (MLA)-positive, where there were no data for the latter. Almost all of the 962 rodent carcinogens and in vivo genotoxins were detected by an in vitro battery comprising Ames+MNvit. An additional 11 carcinogens and six in vivo genotoxins would apparently be detected by the MLA, but many of these had not been tested in the MNvit or CAvit tests. Only four chemicals emerge as potentially being more readily detected in MLA than in Ames+MNvit--benzyl acetate, toluene, morphine and thiabendazole--and none of these are convincing cases to argue for the inclusion of the MLA in addition to Ames+MNvit. Thus, there is no convincing evidence that any genotoxic rodent carcinogens or in vivo genotoxins would remain undetected in an in vitro test battery consisting of Ames+MNvit.

Exposure to mosquito coil smoke may be a risk factor for lung cancer in Taiwan

Background

About 50% of lung cancer deaths in Taiwan are not related to cigarette smoking. Environmental exposure may play a role in lung cancer risk. Taiwanese households frequently burn mosquito coil at home to repel mosquitoes. The aim of this hospital-based case-control study was to determine whether exposure to mosquito coil smoke is a risk for lung cancer.

Methods

Questionnaires were administered to 147 primary lung cancer patients and 400 potential controls to ascertain demographic data, occupation, lifestyle data, indoor environmental exposures (including habits of cigarette smoking, cooking methods, incense burning at home, and exposure to mosquito coil smoke ), as well as family history of cancer and detailed medical history.

Results

Mosquito coil smoke exposure was more frequent in lung cancer patients than controls (38.1% vs.17.8%; p<0.01). Risk of lung cancer was significantly higher in frequent burners of mosquito coils (more than 3 times [days] per week) than nonburners (adjusted odds ratio = 3.78; 95% confidence interval: 1.55-6.90). Those who seldom burned mosquito coils (less than 3 times per week) also had a significantly higher risk of lung cancer (adjusted odds ratio = 2.67; 95% confidence interval: 1.60-4.50).

Conclusion

Exposure to mosquito coil smoke may be a risk factor for development of lung cancer.

Genotoxicity induced by fine urban air particulate matter in the macrophages cell line RAW 264.7

Recent studies support a participation of fine airborne particulate matter (PM) with an aerodynamic diameter less than 2.5 microm in the effects of air pollutants on health. Particulate matter was collected in an urban area of L'Aquila during the winter 2004. Fine particulate samples were analyzed by X-ray photoelectron spectroscopy (XPS) to determine the chemical inventory of the aerosol particle surfaces and to evaluate the weight of characteristic functional groups of the most frequent carbon-containing organic pollutant compounds (C-C/C-H, C-O/C-N, C=O, COOH). The most important contributor to the mass of fine particulate matter was carbon. The overall purpose of this work was to determine the in vitro toxicity and genotoxicity of fine PM in cultured macrophages (RAW 264.7 cells) since the biological target of inhaled PM are the pulmonary epithelium and resident macrophages. In parallel in vitro toxicity assays were used including cell viability and apoptosis. Genotoxicity was evaluated by the micronucleus (MN) assay. The viability of macrophages was assessed by the MTT method; apoptosis by an ELISA test for programmed cell death (PCD) was determined after RAW 264.7 cells treatment. Concentration of 1, 3 and 10 microg/cm2 of fine particles induced micronuclei in a dose-dependent manner. We also compared the effects of fine PM with those of fine carbon black particles (CB) in similar doses. Fine carbon black particles were consistently less genotoxic than the fine atmospheric particles, suggesting that the contaminants adsorbed on them (i.e. carbon-containing organic compounds in addition to metal oxides and metal salts) are involved in genotoxicity. Fine PM reduced cellular proliferation. Overall, the results presented here demonstrate the utility of in vitro tests in mouse cells for testing genotoxicity of urban air particulate matter.

Aliphatic aldehydes and allethrin in mosquito-coil smoke

Presence of aliphatic aldehydes and allethrin in the smoke produced by two brands of mosquito-coil was determined by high performance liquid chromatography. It was observed that burning mosquito-coil produces a greater amount of formaldehyde, acetaldehyde and acrolein in the gaseous phase, whereas lesser amount of particulate-bounded aldehydes. Aldehydes bounded in particulates were, however, enriched in terms of concentration. Allethrin was found to occur only in particulates of 0.1-1.0 micron size. The results reveal that allethrin may not be capable of attacking the mosquitoes effectively.

Micronucleus assay in pulmonary alveolar macrophages, a simple model to detect genotoxicity of environmental agents entering through the inhalation route

A simple and short-term micronucleus (MN) test in pulmonary alveolar macrophages (PAMs) of rats has been developed to assess potential genotoxic effects of gaseous environmental agents. The protocol has been tested in model experiments with indoor air pollutants like mosquito coil smoke (MCS) and mosquito mat vapour (MMV). Smears of pulmonary lavage fluid collected in hypotonic (0.56%) KCl solution were fixed in absolute methanol and stained in Giemsa (10%). Characteristically the large size of the PAMs facilitates easy scoring of MN. An interval of 32 h post exposure seems to be suitable for MN preparation. A comparison of the concentration-response data on CAs (at 24 h post exposure) and MN (at 32 h post exposure) clearly reveals the validity of the MN assay in PAMs.

Alkaline single cell gel (comet) assay and genotoxicity monitoring using bullheads and carp

Monitoring genotoxicity of the environment using endemic organisms as sentinels requires the development of sensitive assays. Toward this end, we explored the feasibility of applying the alkaline single cell gel (SCG) or "comet" assay. This approach involves detection, under alkaline conditions, of cell DNA fragments which, on electrophoresis, migrate from the nuclear core, resulting in a "comet with tail" formation. Tail length has been correlated with level of genotoxicant exposure in a number of organisms. The fish used in this study were benthic feeding bullheads (Ameiurus nebulosus) and carp (Cyprinus carpio). On electrophoresis of erythrocyte DNA under alkaline conditions, we found a linear increase in the tail length/core width ratio over a broad range of cyclophosphamide doses. Freshly caught bullheads from seven different sites showed a wide range of DNA damage. Bullheads from Big Creek (western Lake Erie), Hamilton Harbour (western Lake Ontario), and the Detroit River gave ratios of 3.81 to 4.65. Based on polycyclic aromatic hydrocarbon (PAH) and polychlorinated biphenyl (PCB) levels, the sediment at these three sites is considered to be heavily polluted. Bullheads from southern Lake Huron, which is relatively clean, and from a fish hatchery in Brockport, New York, gave ratios between 1.30 and 1.40. Bullheads from Big Creek, maintained in the laboratory for 3 months, gave ratios which approached those seen in hatchery-bred fish. Results for carp were similar. Carp from Big Creek gave ratios of about 4.50, while carp from Lake Huron and laboratory-maintained carp gave values of 1.23 and 1.36, respectively. The results of the SCG procedure in bullheads and carp indicate that this assay is extremely sensitive and should be useful in detecting DNA damage caused by environmental contaminants.