Shahad Mohammed Najeb, Ausama Ayob Jaccob, Muhsin S G Al-Moziel, Hayder Mohammed Abdulhameed
{"title":"Cardioprotective and antioxidant effects of taxifolin and vitamin C against diazinone-induced myocardial injury in rats.","authors":"Shahad Mohammed Najeb, Ausama Ayob Jaccob, Muhsin S G Al-Moziel, Hayder Mohammed Abdulhameed","doi":"10.5620/eaht.2022002","DOIUrl":"https://doi.org/10.5620/eaht.2022002","url":null,"abstract":"<p><p>In Iraq, excessive exposure to insecticides is increasingly becoming uncontrollable, the objective of this work was to assess the possible ameliorative role of taxifolin and vitamin c against diazinon-induced myocardial injury in rats. 36 sprague female rats divided into 6 groups of 6 rats each. Group 1 received diazinone 20 mg/kg gavaged for 30 days. Group 2 received taxifolin (25 mg/kg) and vitamin C (100 mg /kg) co-administered together and gavaged daily for 30 days before oral diazinone (20 mg/kg). Group 3 and group 4 were treated with taxifoline (25 mg/kg) and vitamin C (100 mg /kg) respectively, gavaged separately for 30 days before diazinone (20 mg/kg) administration. group 5 was considered as control 1 received taxifolin (25 mg/kg) and vitamin C (100 mg /kg) co-administered together and gavaged daily for 30 days. The last group, group 6 considered as control 2 which received vehicle of diazinon. Rats' weights, water and food intake were measured and the general vital signs of rats were observed and noted. At the end of study, rats are sacrificed, blood withdrawn for biochemical analysis and heart were excised for glutathione peroxidase and pathological evaluation. Significant increase in body weights in all treated and control groups except group 1. Troponin, LDH, AST and ALT levels were significantly increased in group 1 revealing the existence of ischemia and damage in hearts. Treatment with taxifolin and vitamin C combination reduced their levels significantly to concentrations comparable to that in the control groups. Such finding supported by histopathological observation. Moreover, this study showed that diazinon administration significantly deteriorated lipid profile, co-administration of taxifolin and vitamin C was resulted in a significant improvement in lipid profile associated with increased in glutathione peroxidase values showing significant improvement in antioxidant levels. Sub-acute administration of pharmacological doses of taxifolin and vitamin C exerts cardioprotective effects against diazinon-induced myocardial injury in rats.</p>","PeriodicalId":11867,"journal":{"name":"Environmental analysis, health and toxicology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/24/ed/eaht-37-1-e2022002.PMC9058105.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39578914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Victor Uchenna Okechukwu, Daniel Omeodisemi Omokpariola, Valentine Ifenna Onwukeme, Eucheria Nkiru Nweke, Patrick Leonard Omokpariola
{"title":"Pollution investigation and risk assessment of polycyclic aromatic hydrocarbons in soil and water from selected dumpsite locations in rivers and Bayelsa State, Nigeria.","authors":"Victor Uchenna Okechukwu, Daniel Omeodisemi Omokpariola, Valentine Ifenna Onwukeme, Eucheria Nkiru Nweke, Patrick Leonard Omokpariola","doi":"10.5620/eaht.2021023","DOIUrl":"https://doi.org/10.5620/eaht.2021023","url":null,"abstract":"<p><p>The transfer ratio of polycyclic aromatic hydrocarbons (PAHs) from soil dumpsite to borehole water is dependent of polluting source and exposure matrices that causes immerse health risk to man and environment over a period of time. PAHs were assessed in selected soil dumpsite and borehole water located at Rivers state (Eleme, Eliozu, Eneka, Oyigbo, and Woji) and Bayelsa state (Yenagoa), Nigeria. Soil samples were collected at four different points 30 m (North, South, East and West) locations at a depth of 15 cm for each dumpsite using soil auger while control samples were collected 200 m away (farmland), where there were little anthropogenic activities and no presence of active dumpsites. Borehole water samples were collected from 300 m distance, which were packaged in an amber container, labeled, and transported to the laboratory for analysis. Standard analytical methods were employed. PAHs concentrations were analyzed using gas chromatography- mass spectrometry (GC-MS) after extraction of water and soil using liquid-liquid and soxhlet extraction methods respectively and clean-up of the extracts, thereafter the laboratory data generated were subjected to statistical analysis. Total PAHs (ΣPAHS) concentrations in soil samples from the study sites ranged from 2.4294 mg/kg in Yenagoa to 5.1662 mg/kg in Eleme while in water samples the total PAHs ranged from 1.3935 mg/L in Woji to 3.009 mg/L in Eleme. The total PAH concentrations in the soil were above the Agency for Toxic Substances and Disease Registry levels of 1.0 mg/kg for a considerably contaminated site except for the control sites. The total concentration of carcinogenic PAHs ranged from 0.0038 to 1.1301mg/kg in soil samples and 0.0014 to 0.9429 mg/L in borehole water samples, therefore raising concern of human exposure via food chain. The results indicate that low molecular weight PAHs were more dominant than high molecular weight PAHs in both soil and water samples, however molecular diagnostic ratio shows that pyrogenic activities are major sources of PAHs as compared to petrogenic origin. Multivariate analysis (principal component analysis and Pearson correlation) showed strong negative correlation implying that they were from dissimilar sources and different migratory route. Cancer and non-cancer risk showed that children were more at risk compared to adults, where inhalation exposure were major contribution as compared to ingestion and dermal exposure, as such there is a need to implement regulatory laws on indiscriminate release of PAHs contaminants to maintain sustainability.</p>","PeriodicalId":11867,"journal":{"name":"Environmental analysis, health and toxicology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/21/f8/eaht-36-4-e2021023.PMC8850164.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39571565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"N-Acetyl cysteine mitigates histopathological changes and inflammatory genes expressions in the liver of cadmium exposed rats.","authors":"Jalal Aala, Asghar Beigi Harchegani, Hanieh Akhlaghi Monsef, Zhaleh Mohsenifar, Pirooz Ebrahimi, Mohammad Reza Parvizi","doi":"10.5620/eaht.2021024","DOIUrl":"https://doi.org/10.5620/eaht.2021024","url":null,"abstract":"<p><p>This study aimed to consider the expression of Nrf2, NLRP3 and caspase 1 genes, as well as oxidative stress, and the protective role of N-acetyl cysteine (NAC) in the liver of rats treated with cadmium (Cd). Male rats were randomly divided into five groups including G1 (control), G2 (single dose of Cd), G3 (continuous dose of Cd), G4 (single dose of Cd + NAC), and G5 (continuous dose of Cd + NAC). Levels of malondialdehyde (MDA) and total antioxidant capacity (TAC) were measured. Expression of Nrf2, NLRP3 and caspase 1 genes was considered using RT-PCR. NAC treatments significantly improved TAC, but decreased MDA values in rats that exposed to continuous dose of Cd (p<0.05). Exposure to continuous dose of Cd caused a significant decrease in Nrf2 expression by 2.46-fold (p<0.001), but enhanced expression of NLRP3 and Caspase 1 genes by 3.13-fold and 3.16-fold), respectively (p<0.001). Compared to rats that treated to continuous dose of Cd, NAC supplementation enhanced the expression of Nrf2 by 1.67-fold (p<0.001) and reduced the expression of NLRP3 and Caspase 1 genes by 1.39-fold (p<0.001) and 1.58-fold (p<0.001), respectively. Down-regulation of Nrf2 and overexpression of NLRP3 and caspase 1 seems to be one of the main mechanisms of Cd toxicity on liver tissue. NAC protects liver tissue against Cd-induced oxidative injuries via enhancement of Nrf2 expression and reduction of NLRP3 and caspase 1 genes.</p>","PeriodicalId":11867,"journal":{"name":"Environmental analysis, health and toxicology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/15/d8/eaht-36-4-e2021024.PMC8850162.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39571566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alexander Iheanyichukwu Opara, Casmir Zanders Akaolisa, Chigozie Osita Akakuru, Amarachi Udoka Nkwoada, Francis Chizoruo Ibe, Andrew Wirnkor Verla, Ikechukwu Chigozie Chukwuemeka
{"title":"Particulate matter exposure and non-cancerous inhalation health risk assessment of major dumpsites of Oerri metropolis, Nigeria.","authors":"Alexander Iheanyichukwu Opara, Casmir Zanders Akaolisa, Chigozie Osita Akakuru, Amarachi Udoka Nkwoada, Francis Chizoruo Ibe, Andrew Wirnkor Verla, Ikechukwu Chigozie Chukwuemeka","doi":"10.5620/eaht.2021025","DOIUrl":"https://doi.org/10.5620/eaht.2021025","url":null,"abstract":"<p><p>Numerous particulates are released from the dumpsites in Owerri metropolis and later dispersed to other areas in the environment where they cause adverse health challenges to the inhabitants. To analyze the PM concentration, field measurements were carried out at seven major dumpsites in the Owerri Metropolis. Estimates of the possible health risks as the result of exposure to airborne particulate matter (PM2.5, PM10, etc.) were performed using the US Environmental Protection Agency human health risk assessment framework. A scenario assessment approach in which normal exposure and worst-case scenario were adopted for acute and chronic exposure periods for infants, children, and adults. The concentrations of PM 2.5 which ranged from 122.30-501.76 μg/m3 at the dumpsites exceeded the WHO 24hr annual mean maximum exposure limit. The Nigerian National Ambient Air Quality Standard allowable limit for PM10 was exceeded by most of the dumpsites. Hazard quotient > 1 was exceeded for PM 2.5 by nearly all dumpsites and is likely to cause health challenges. The results showed that under monthly conditions, both PM2.5 and PM10 concentration levels at the dumpsites have the potential to cause adverse health effects when for infants, children, and adults on acute or chronic bases. Actions should be taken to regulate such PM exposure and to raise public awareness for the inhabitants of the affected areas. In conclusion, regular monitoring is therefore needed to decrease the ambient particulate matter (PM) concentrations in the study area.</p>","PeriodicalId":11867,"journal":{"name":"Environmental analysis, health and toxicology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/97/41/eaht-36-4-e2021025.PMC8850163.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39746321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Trend of asthma prevalence among children based on regional urbanization level in Japan; 2006-2019.","authors":"Tasuku Okui","doi":"10.5620/eaht.2021027","DOIUrl":"https://doi.org/10.5620/eaht.2021027","url":null,"abstract":"<p><p>Although it has been known that the prevalence of asthma tends to be higher among children in the metropolitan areas of Japan, trends of the prevalence with respect to the regional urbanization level has not been investigated in recent years. We investigated trends in the prevalence of asthma among children and air pollutant concentrations by regional urbanization levels using data from the School Health Statistics Survey in Japan from 2006 to 2019. We calculated the age-standardized prevalence of asthma for each year, gender, regional urbanization level, and annual percent change (APC). In addition, the slope index of inequality (SII) and relative index of inequality (RII) were calculated for evaluating disparity in age-standardized asthma prevalence depending on regional urbanization levels. Moreover, we calculated the mean of the annual average values by regional urbanization levels for sulfur dioxide (SO2), nitrogen dioxide (NO2), suspended particulate matter (SPM), carbon monoxide (CO), and photochemical oxidant (Ox) from 2006 to 2018. We found that the age-standardized prevalence significantly decreased in the periods in the metropolis for males and females, and the degree of the decrease was largest in the metropolis. Conversely, the age-standardized prevalence increased in towns and villages, and the APC was greater than zero. In addition, both the SII and RII showed significant decreasing trends in the study period, and the regional disparity shrank over the years. Moreover, concentrations of the air pollutants were highest in the metropolis throughout the years except for Ox, whereas the difference in the concentrations of NO2, SPM, and CO decreased between the metropolis and the other areas over the years. In conclusion, disparity in asthma prevalence depending on regional urbanization level decreased from 2006 to 2019, and there is a possibility that regional difference in trend of the air pollutants is related to the result.</p>","PeriodicalId":11867,"journal":{"name":"Environmental analysis, health and toxicology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/21/00/eaht-36-4-e2021027.PMC8850166.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39813366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ismail Saleh, Syamsir Syamsir, Vita Pramaningsih, Hansen Hansen
{"title":"The use of green mussel as bioindicator of heavy metal pollution in Indonesia: a review.","authors":"Ismail Saleh, Syamsir Syamsir, Vita Pramaningsih, Hansen Hansen","doi":"10.5620/eaht.2021026","DOIUrl":"https://doi.org/10.5620/eaht.2021026","url":null,"abstract":"<p><p>Asian green mussel is a marine animal that is used as food by most Indonesians. The mussels are widely cultivated in tropical countries such as Indonesia, Malaysia, Thailand, and other Asian countries. The mussel, known as perna viridis, is marine biota that is a filter feeder in the waters. Therefore, the quality of its meat is greatly influenced by the quality of the sea in its habitat. It is a food that is quite popular with the community but can endanger public health due to the accumulation of heavy metals. This study used a literature review by collecting data related to heavy metal concentrations in green mussel tissue in Indonesia. The results showed that the mussels from several sampling locations still exceeded the maximum acceptable limits of lead (Pb), mercury (Hg), and cadmium (Cd) concentration according to the standards of the food and drug administration of the Republic of Indonesia. Consumption of green mussels can increase health risks if you frequently consume them from cultivating or catching locations that have been contaminated with heavy metals.</p>","PeriodicalId":11867,"journal":{"name":"Environmental analysis, health and toxicology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/ec/89/eaht-36-4-e2021026.PMC8850165.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39746322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Detection of aflatoxin producing Aspergillus flavus from animal feed in Karnataka, India.","authors":"Pethannan Rajarajan, Katherin Sylvia, Malaiyarasa Pandian Periasamy, Maheswari Subramanian","doi":"10.5620/eaht.2021017","DOIUrl":"https://doi.org/10.5620/eaht.2021017","url":null,"abstract":"<p><p>Aflatoxins are toxic carcinogenic secondary metabolite produced by Aspergillus flavus and are responsible for contamination in animal feed. The aim of the study was to determine the prevalence of aflatoxin contamination in animal feed in Karnataka state, India. The screening was performed by desiccated coconut agar and quantification of aflatoxin by liquid ammonia vapor test, TLC and ELISA. A total of 29 samples received from different places of Karnataka were analysed for aflatoxin B1. Out of 29 animal feed sample aflatoxin B1 detected in 12 samples representing 41.38% at average concentration of 288.50 μg/kg. Out of 42 isolates screened in animal feed, Aspergillus flavus was found to be in 86.2% and Aspergillus niger was 24.1%. It was observed that out of 42 isolates analyzed from animal feed, aflatoxin B1 was detected in 12 samples. Aflatoxin B1 is the most common contaminant and the method is more sensitive in screening and detection of aflatoxin B1 in the animal feed.</p>","PeriodicalId":11867,"journal":{"name":"Environmental analysis, health and toxicology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/3f/7f/eaht-36-3-e2021017.PMC8598409.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39278490","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Urinary toluene levels and adverse health symptoms among automotive garage workers, Nakhon Si Thammarat province, Thailand.","authors":"Somsiri Decharat","doi":"10.5620/eaht.2021018","DOIUrl":"https://doi.org/10.5620/eaht.2021018","url":null,"abstract":"<p><p>To determine their urinary toluene levels, to describe the workers' hygiene behaviors and the prevalence of adverse health symptoms among automotive garage workers exposed to chemical substances. A cross-sectional descriptive study was conducted by interviewing among automotive garages located in the Nakhon Si Thammarat province, Thailand. During between 1 November 2020 and 31 December 2020. A total of 140 automotive garages workers were selected using a purposive sampling method. The questionnaire was conducted via face-to-face interview and the toluene was quantified using gas chromatography. Descriptive statistics were computed for the variables. Risk factors were evaluated using multiple logistic regression analysis. Adjusted odds ratio (ORadj) and 95% confidence interval (CI) were presented as statistically significant when the p value was < 0.05. The Mann-Whitney U test was used to compare the medians of continuous variables of the two groups. The prevalence of skin effects (60.71%); respiratory tract irritation (49.29%); nausea (46.43%); and dizziness (40.71%) was remarkable in the automotive garage workers. Several socio-demographic variables were significantly associated with increased skin effects, respiratory tract irritant, nausea, and dizziness. The median urinary toluene level of the automotive garage workers was 145 μg/L (range, 12.0-958.0 μg/L) which the median urinary levels and demographic characteristics, occupational lifestyle, personal protective equipment used, hygiene behavior, and adverse health symptoms had significantly significant different (p< 0.05).Urine is one of the most useful a sample for biomonitoring of occupational exposure to toluene. Personal hygiene is important for the automotive garage workers, and it should be emphasized in education programs.</p>","PeriodicalId":11867,"journal":{"name":"Environmental analysis, health and toxicology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/53/88/eaht-36-3-e2021018.PMC8598402.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39278923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Acute and sublethal intoxication of malathion in an Indian major carp, Labeo rohita: haematological and biochemical responses.","authors":"Juginu Mankuzhiyil Sivanandan, Binukumari","doi":"10.5620/eaht.2021016","DOIUrl":"https://doi.org/10.5620/eaht.2021016","url":null,"abstract":"<p><p>This study aimed to determine the median lethal concentration (96-h LC50), acute and sublethal effects of malathion, an organophosphorus pesticide on hematological and biochemical responses in an Indian major carp, Labeo rohita. In this study, the LC50 value of malathion for 96 h was found to be 3.4 ppm. During acute (3.4 ppm) and sublethal [1/10th of 96 h LC50 value (0.34 ppm) studies, all the hematological parameters except WBC were significantly decreased (p<0.05). Besides, when compared with the control group, a significant (p<0.05) decrease in biochemical activity was also observed in malathion treated fish during acute and sublethal exposure periods. These results suggest that the tested concentrations of malathion could have significant adverse effects on the hematological and biochemical parameters of fish, Labeo rohita. The changes in the parameters can be effectively used to determine the impact of malathion in the aquatic ecosystem.</p>","PeriodicalId":11867,"journal":{"name":"Environmental analysis, health and toxicology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/f5/25/eaht-36-3-e2021016.PMC8598410.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39629117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Histopathological changes in the lungs of rats instilled with Korean chrysotile.","authors":"Jeong Hee Han, Yong Hyun Chung, Cheol Hong Lim","doi":"10.5620/eaht.2021014","DOIUrl":"https://doi.org/10.5620/eaht.2021014","url":null,"abstract":"<p><p>To evaluate the pulmonary toxicity of Korean chrysotile (KC), 1 or 2 mg of KC (low- and high-concentration groups, respectively) was instilled in the lungs of Sprague-Dawley rats by a single intratracheal instillation. The lungs were examined using a light microscope at several time points (5 days, 5 weeks, and 10 weeks). Up to 10 weeks after KC instillation, differences were observed in the pathological reactions and ultimately in lung recovery between the two groups. At 5 days after KC instillation, lung weight increased and severe bronchiolitis obliterans developed in proportion to the KC concentration administered. From 5 to 10 weeks after KC administration, the lung weight of the low-concentration group increased and bronchiolitis obliterans worsened. In the high-concentration group, the lung weight and the severity of bronchiolitis obliterans at 10 weeks after administration of KC declined compared to those at 5 weeks. In conclusion, the effects of KC on lung tissue were initially found to be more influenced by the amount of fiber, but over time, the effects were influenced by the residual fibrous material in the lung tissue and its biodurability.</p>","PeriodicalId":11867,"journal":{"name":"Environmental analysis, health and toxicology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/a3/99/eaht-36-3-e2021014.PMC8598405.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39278488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}