Environmental analysis, health and toxicology最新文献

This study aims to analyze the trends in the Japanese prevalence of asthma, allergic rhinitis, and atopic dermatitis by using age-period-cohort (APC) analysis. Data regarding the prevalence of diseases from 1999 to 2017 were collected from Patient Survey in Japan. The data were divided according to age groups ranging from 0-4 years old up to 65-69 years old in 5-year increments. A cohort was defined for each age group of each year with a one-year shift, and cohorts born from 1930-1934 up to 2013-2017 were examined. We used Bayesian APC analysis to decompose the changes in prevalence into age, period, and cohort effects. Results show that the period effect for asthma began to increase in 2008, and those of allergic rhinitis and atopic dermatitis began to increase in 1999. The cohort effects for asthma and atopic dermatitis increased rapidly in cohorts born from approximately 1950 to 1980 and then decreased thereafter. Furthermore, the cohort effect for allergic rhinitis increased from cohorts born in approximately the late 1970s for men and in 1990 for women. The time points with increasing cohort effects for asthma and atopic dermatitis are consistent with the history of air pollution accompanied by rapid economic growth in Japan. The onset of the increased cohort effect for allergic rhinitis was also relatively consistent with the time point at which the mass scattering of pollen began.

Development of modified polymers is the focused area of research for developing stable, effective, sustainable and economical polymeric materials for developing different drug delivery systems. Modification of chitosan by catechol functionalization is useful for developing chitosan derivative with the improved mucoadhesive property. Present study was designed to perform single dose acute oral toxicity on chitosan-catechol conjugates in Swiss albino mice as per international guidelines. Oral administration of modified chitosan did not exhibit any significant change in body weight, behavioural pattern, haematology, food intake and clinical symptoms in the experimental animals. In the histopathological study, no pathological changes were observed in the vital organs of mice when administered perorally with 300 mg/kg and 2,000 mg/kg body-weight doses of chitosan-catechol polymeric conjugates. Overall, it was concluded from the acute oral toxicity study that the oral administration of chitosan-catechol conjugates in mice did not produce any toxicity. Hence, chitosan-catechol conjugates could be designated and recommended as safe polymeric material for developing different drug delivery systems.

Evidence suggests that the relationship between arsenic metabolism and diseases, including metabolic syndrome, is complex. The aim of this study was to evaluate the different types of arsenic methylation and its association with metabolic syndrome in an arsenic endemic area. A cross-sectional study was conducted on 132 subjects from Shahid-Abad Village, Qazvin province, Iran (arsenic endemic area). Demographic characteristics, metabolic syndrome, and urinary arsenic species, including iAs (inorganic arsenic), MMA (monomethylarsonic acid), and DMA (dimethylarsinic acid) were measured for all patients and their relationship was analyzed by appropriate statistical methods. In this study, 34.5% of the participants had metabolic syndrome. The decrease in %MMA, increase in %DMA and increase in secondary methylation index (DMA/MMA) were associated with increased risk of metabolic syndrome (p<0.05). We did not find any association between the incidence of metabolic syndrome with primary methylation index (MMA/iAs) and %iAs (p>0.05). This study showed that the prevalence of metabolic syndrome was significantly higher in people with metabolic syndrome than in the general population. A closer examination revealed that the secondary methylation index is related to the metabolic syndrome and its components. Given the higher prevalence of cardiovascular disease and diabetes in patients with metabolic syndrome, it is necessary to change the pathogenesis of the disease using comprehensive management methods for decreasing patient complications.

Bacterial remediation of heavy metal polluted soil and effluent from paper mill was investigated using standard analytical methods. The paper mill was visited for 6 months at interval of 30 days to collect soil and effluent samples for the analysis. The pH of soil was slightly alkaline while effluent was acidic. There was a significant increase (P < 0.05) in total organic carbon (TOC) of soil; and turbidity, biochemical oxygen demand (BOD), chemical oxygen demand (COD) and TOC of effluent when compared to control. Bacteria isolated from the samples were grouped into two and used to remediate eight heavy metals. The remediation experiment consists of three treatments; Treatment 1 (treated with proteobacteria), Treatment 2 (treated with non-proteobacteria) and Treatment 3 (without bacteria) (control experiment). Result of the remediation study showed that there was a significant decrease (P < 0.05) in Treatment 1 and Treatment 2 of all the heavy metals in soil and effluent samples from day 30-180 when compared to day 0. The rate of removal of heavy metals in soil was highest in Treatment 1 for chromium (Cr; 0.00846 day-1) and lowest in Treatment 1 for cadmium (Cd; 0.00403 day-1) while the rate of removal in effluent was highest in Treatment 1 for zinc (Zn; 0.01207 day-1) and lowest in Treatment 1 for Cd (0.00391 day-1). It was concluded that bacteria isolated from soil and effluent samples were capable of remediating the concentration of Pb, arsenic (As), Cr, Zn and nickel (Ni) heavy metals.

Humidifier disinfectant damages caused by the misuse of humidifier disinfects, such as polyhexamethylene guanidine (PHMG), resulted in chemical disasters in South Korea in 2011. About four million people were exposed to humidifier disinfectants (HDs) in the 17 years between 1994 and 2011. Although fatal lung damage was initially reported, investigations into the victims' injuries revealed that the damage was not limited to the lungs, but that systemic damage was also confirmed. Considering the spread of HD from the lungs to the whole body, the toxic effects of PHMG from reactive oxygen species (ROS), NOTCH signaling pathways, and mitochondrial dysfunction resulted in endothelial damage in the lungs, blood vessels, liver, kidneys, bone marrow, nerves, and muscles. The main toxic mechanisms involved in HD damage may be the NOTCH pathway and mitochondrial damage. There are many case reports which include neurologic disorders (ADHD, depression, posttraumatic stress disorder), muscular disorder (exercise intolerance, myalgia), energy metabolism disorder (chronic fatigue syndrome), and immunologic disorder (rheumatoid arthritis) in HDs victims. These case reports involve multi-system involvement in HDs victims. Further well-designed study is needed to clarify whether mitochondrial dysfunction is associated with multi-organs involvement in HDs victims.

This study was carried out to investigate heavy metals concentrations: lead (Pb), cobalt (Co), cadmium (Cd), zinc (Zn), nickel (Ni), copper (Cu) and manganese (Mn) in Musa paradisiaca (plantain), Zea mays (maize), Cucumeropsis manii (melon), Manihot esculenta (cassava) and soil samples from dumpsites in Onne, Eleme Local Government Area, Rivers State, Nigeria. The plant leaf and soil samples were measured for heavy metals concentrations using atomic absorption spectrophotometer. The health risk index (HRI) of the heavy metals following the consumption of these plant materials by the populace was estimated using standard protocols. The heavy metals concentrations in the leaf samples ranged from 0.012-14.712 mg/kg, whereas those of the soil samples were within the range of 2.543-16.459 mg/kg. Cd concentrations in the soil and leaf samples were above the maximum permissible level according to the World Health Organization (WHO). The bioaccumulation of the heavy metals followed the trend: (M. paradisiaca) Zn > Pb > Co > Mn > Cu > Cd > Ni; (Z. mays) Mn > Pb > Co > Zn > Cu > Cd > Ni; (C. mannii) Mn > Co > Pb > Cu > Zn > Cd > Ni; (M. esculenta) Zn > Pb > Mn > Cu > Co > Ni > Cd. The highest bioaccumulation of the heavy metals occurred in M. esculenta. The estimated HRI of Pb in M. esculenta was greater than 1. HRI > 1 was indicative that the consumer population is not safe. Cassava-based meals from the dumpsites contained Pb at toxic level, whereas Co, Cd, Zn, Ni, Cu, and Mn concentrations in plantain-, maize- and melon-based meals were relatively within safe limits.

Geo-environmental assessment of activities of auto-mechanics at Alaoji Aba and Elekahia Port Harcourt, both in the Niger Delta region, Southern Nigeria were carried out with the main objective of determining the extent of soil contamination arising from anthropogenic activities within mechanic villages (MVs). Geochemical analysis of soil samples from the study area revealed that the concentrations of the trace metals ranged from <1 mg/kg for chromium (Cr) to 1,925 mg/kg for the lead (Pb). Soil analysis for polycyclic aromatic hydrocarbon (PAH) and total petroleum hydrocarbon (TPH) across the area revealed concentrations ranging from <0.02 to 1.80 mg/Kg and from <1.00 to 38,327 mg/kg respectively. Elevated levels of the heavy metals and TPH were observed at MV in Alaoji Aba when compared to MV in Elekahia Port Harcourt, and the control sites. These could be attributed to contamination due to the presence of these auto-mechanics in the area for over thirty years. The concentration of Pb and Cd recorded in some sample points were above USEPA (United State Environmental Protection Agency) and the National Environmental Standards and Regulations Enforcement Agency (NESREA) permissible limits. Results of PAH analysis showed the presence of naphthalene, phenanthrene, pyrene, fluorene, benzo(a)anthracene, acenaphthene, methylnaphthalene. Risk assessment analysis showed significant geo-accumulation values for Cd and Pb indicating heavy contamination. The monomial risk factor of the heavy metals in the MVs are in the order Cd>Pb>Cr, while potential ecological risk index analysis showed values indicating very high risk, considerable risk and a moderate risk to the area under study as well as the surrounding environment. These results suggest that the soils from the MVs which represent the mechanic workshops at Alaoji Aba and Elekahia Port Harcourt are considered to be of pollution concern due to elevated Pb and Cd levels. Hence, there is a serious need to regularly monitor the activities of auto-mechanics in the study area.

A mixture of 5-chloro-2-methylisothiazol-3(2H)-one/2-methylisothiazol-3(2H)-one (CMIT/MIT) had been used as an active ingredient in humidifier disinfectants (HDs). Owing to its high reactivity, the atmospheric concentration of CMIT/MIT, following its use in HD, would be lower than expected assuming that it is removed by ventilation only. In order to evaluate the exposure concentration of CMIT/MIT used as an HD, room-scale chamber studies were conducted under plausible use of three different HD doses at air change rates (ACR) of 0.3, 0.5, and 1.0 h-1. Atmospheric CMIT/MIT was sampled using two serial impingers containing deionized water after the attainment of steady state. Water samples in which CMIT/MIT was dissolved were concentrated using a cosolvent evaporation method with efficiencies of 35.5 and 77.9% for CMIT and MIT, respectively. The estimated air concentration, assuming that all the CMIT/MIT is absorbed in deionized water, increased linearly with increasing emission rate, but was independent of the ACR. This indicates that the removal rate of CMIT/MIT via chemical reactions is more than the removal rate by ventilation. Further investigations on homogeneous and heterogeneous chemical reactions of CMIT/MIT under ambient conditions are necessary to understand the actual exposure concentration of the mixture in HD.

Mixture of xenobiotics in Olusosun landfill leachates (OSL) induced somatic and germ cell genotoxicity in eukaryotic cells. However, whether the DNA-damaged germ cells can increase reproductive failure, embryotoxicity and/or teratogenicity during fertilization remained unclear. The study herein investigated reproductive toxicity and embryotoxic effects of OSL in mice using abnormal sperm morphology and dominant lethal mutation assays. Six mice per group were exposed to 0.5 mL of 5, 10, 25, and 50% OSL (v/v, leachate/distilled water) for 5 consecutive days. Similar treatment was giving to distilled water and cyclophosphamide (20 mg/kg body weight), as negative and positive control groups, respectively. At 35 day post-treatment, the mice were sacrificed and examined for cauda epididymal abnormal sperm morphology, testicular weight change and histopathological lesions. Male mice were mated to untreated nulliparous females (1 treated male per 2 untreated females) until vaginal plugs were observed. Pregnant females were sacrificed on 14th day post-mating and uterine content examined for number of implants per female, resorptions, and live and dead fetuses. OSL significantly increased teratozoospermia by 31.02% with amorphous sperm head having the highest frequency and sperm with two heads, the least. Histology of the testes revealed congestion of the interstitial blood vessels, spermatid retention and disorganization of the germinal epithelium from the basal compartment. OSL insignificantly increased absolute and relative testes weights but reduced body weight of exposed mice. There was insignificant induction of dominant lethal mutation, although low fertility was observed in the treated mice. The analyzed physico-chemical parameters and heavy metals/metalloids in OSL were higher than permissible limits. The metals, physico-chemical parameters and other unanalyzed substances in OSL induced abnormal sperm morphology, altered testes pathology, but did not significantly induce dominant lethal mutation in mice. Constituents of OSL are toxic to the male reproductive organs in mice and suggests harmful impact on public health. Indiscriminate disposal of solid wastes in the environment should be prevented.

This study was aimed at investigating the neuroprotective effect of Vitexin against lead (Pb) induced neurodegenerative changes in the dorsolateral prefrontal cortex (DLPFC) and working memory in mice. Thirty-two adolescent male albino mice were divided into four groups (n=8). Control group received 0.2 mL of normal saline; Pb group received 100 mg/kg of Pb acetate for 14 days, Vitexin group received 1mg/kg of Vitexin for 14 days, and Pb+Vitexin group received 100 mg/kg of Pb acetate and 1 mgkg of Vitexin for 14 days. Barnes maze test and novel object recognition test were done to ascertain working memory. Histoarchitectural assessment of DLPFC was done with haematoxylin and eosin (H&E), cresyl fast violet and congo red stains. Furthermore, cell count and other morphometric measurements were done. There was significant decline in working memory in the Pb group, but a combination of Pb+Vitexin improved the working memory. Vitexin significantly reduced neuronal death and chromatolysis caused by Pb. Amyloid aggregation was not observed in any of the groups. This study has shown that concurrent administration of Vitexin and Pb will significantly reduce neurodegeneration and improve working memory. However, Pb treatment or Pb+Vitexin treatment does not have any effect on intercellular distance, neuronal length and the cross-sectional area of neurons in layer III of DLPFC.