Exploring the adverse effect of fine particulate matter (PM2.5) on wildland firefighters' pulmonary function and DNA damage.

Chiang Mai encounters severe pollution during the wildfire season. Wildland firefighters encounter various hazards while engaged in fire suppression operations, which encompass significant exposure to elevated concentrations of air pollutants resulting from combustion, especially particulate matter. The adverse effects of wildfire smoke on respiratory health are a significant concern. The objective of this study was to examine the potential adverse effects of PM2.5 exposure on the respiratory function and DNA damage of wildland firefighters. This prospective cohort study conducted in Chiang Mai from January to May 2022 planned to evaluate the health status of wildland firefighters during the pre-peak, peak, and post-peak ambient air pollution seasons. The measurement of PM2.5 was done at every forest fire station, as well as utilizing data from the Pollution Control Department. Participants received general health examinations, spirometry evaluations, and blood tests for DNA damage analysis. Pair t-tests and multiple regression models were used to examine the connection between pulmonary function parameters (FVC, FEV1) and PM2.5 concentration, with a significance level of P < 0.05. Thirty-three peak-season and twenty-one post-peak-season participants were enrolled. Four pre-peak-season wildland firefighters had FVC and FEV1 declines of > 15%. Multiple regression analysis showed a negative association between PM2.5 exposure and FVC% predicted (- 2.81%, 95% CI - 5.27 to - 0.34%, P = 0.027) and a marginally significant negative correlation with FVC (- 114.38 ml, 95% CI - 230.36 to 1.59 ml, P = 0.053). The remaining pulmonary measures showed a statistically insignificant decline. There were no significant changes in DNA damage detected. Wildland firefighters suffered a significant decline in pulmonary function associated with PM2.5 exposure. Spirometry is crucial for monitoring and promptly identifying respiratory issues that occur during wildfire seasons. Further research is recommended to explore DNA damage alterations and their potential association with PM2.5.

The Analysis of Genetic Polymorphism on Mitochondrial Hypervariable Region III in Thai Population.

Mitochondrial DNA (mtDNA) analysis is a genetic marker for human identification, especially matrilineal inheritance. Hypervariable regions (HVR) I and II of mtDNA have been currently performed for human identification worldwide. Further examination of HVRIII has been conducted with the aim of enhancing the power of discrimination. The aim of this research is to provide informative data on the polymorphisms of HVRIII in the Thai population in order to establish a national database for human identification. Thai people who were unrelated through the maternal lineage were recruited for blood collections. The mtDNA was extracted by Chelex extraction, amplified by polymerase chain reaction, and analyzed using Sequencing Analysis Software. The most common mutation in HVRIII was base substitution, followed by deletion and insertion. We discovered 40 unique haplotypes, with haplotype 489C being the most frequent. The haplotype diversity, power of discrimination, and random match probability were 0.8014, 0.7987, and 0.2013, respectively. Five-CA repeats were the most frequently observed in nucleotide positions 514-523. Our database can be employed as supplementary markers in addition to nuclear deoxyribonucleic acid (DNA) markers in forensic investigations. Moreover, the data could potentially enhance genetic identification and anthropological genetics research in Thailand.

Urinary glyphosate kinetics after occupational exposure.

Glyphosate-surfactant herbicides are the most used and imported herbicide in Thailand. Urinary biomonitoring is a very important tool for evaluating glyphosate exposures and its adverse health effects. However, the data for glyphosate toxicokinetics, especially in Asian populations, is relatively limited. The majority of farmers in Thailand have long term experience with glyphosate use, but they generally follow poor safety practices, including insufficient or incorrect use of personal protective equipment during pesticide handling activities. Therefore, this study aimed to determine the toxicokinetics of glyphosate and its metabolite in urine among maize farmers from the northern region of Thailand. The effects of personal protective equipment usage, as well as farmer behavior during work, on urinary glyphosate levels were also studied. Full-voided spot urine samples were collected over the exposure assessment period (0-72 h). Urinary glyphosate levels were determined by liquid chromatography tandem mass spectrometry. The maximum concentration in urine (uCmax), the time of peak glyphosate levels in urine (uTmax), and the urinary elimination half-life (ut1/2) were analyzed using the PKSolver program. The median of uCmax were 27.9, 29.2 and 17.1 µg/g creatinine in a one-time spray group, a two-time spray group Day 1 and a two-time spray group Day 2, respectively. The uTmax was 11.0 h in both study groups. The median of elimination ut1/2 in the one-time and the two-time spray group were 7.0 and 18.1 h, respectively. Although these estimated urinary elimination half-lives may have been impacted by the variation in exposure doses among the participants, it provides the first urinary toxicokinetic data of glyphosate among the Asian population. The toxicokinetic information could be used to increase knowledge and awareness amongst farmers, particularly to minimize the risk of exposure to glyphosate and reduce possible adverse health effects from using pesticide.

Effects of exposure to glyphosate on oxidative stress, inflammation, and lung function in maize farmers, Northern Thailand.

BACKGROUND: Glyphosate is a herbicide which is commonly used in agricultural areas. However, previous studies on glyphosate exposure in farmers and their health are still scarce. METHODS: A longitudinal pre-post study was performed among maize farmers. Information from questionnaires, urine and blood samples, and lung function were collected a day before and a day after glyphosate application in the morning. The urine samples were analyzed using liquid chromatography-tandem mass spectrometry to detect glyphosate levels. Serum samples were analyzed to detect malondialdehyde (MDA), glutathione (GHS), and C-reactive protein (CRP) levels using thiobarbituric acid, dithiobisnitrobenzoic acid, and nephelometry, respectively. Lung function performances were measured using a spirometer. RESULTS: A total of 180 maize farmers met the study inclusion criteria. After glyphosate application, it was found that increased urinary glyphosate levels contributed to increased serum MDA (ß = 0.024, 95% CI = 0.000, 0.0047) and decreased serum GHS (ß = -0.022, 95% CI = -0.037, -0.007), FEV1 (ß = -0.134, 95% CI = -0.168, -0.100), FEV1/FVC (ß = -0.062, 95% CI = -0.082, -0.042) and PEF (ß = -0.952, 95% CI = -1.169, -0.735). CONCLUSIONS: Exposure to glyphosate during glyphosate application had significant effects on oxidative stress and lung function in maize farmers.

Urinary Levels of Sirtuin-1, π-Glutathione S-Transferase, and Mitochondrial DNA in Maize Farmer Occupationally Exposed to Herbicide.

Epidemiologic studies have suggested an association between agrochemical exposure and risk of renal injury. Farmers face great risks to developing adverse effects. The most appropriate biomarker related to renal injury needs to be developed to encounter earlier detection. We aim to study the association between early renal biomarker and occupational herbicide exposure in maize farmers, Thailand. Sixty-four farmers were recruited and interviewed concerning demographic data, herbicide usage, and protective behavior. Two spot urines before (pre-work task) and after (post-work task) herbicide spraying were collected. To estimate the intensity of exposure, the cumulative herbicide exposure intensity index (cumulative EII) was also calculated from activities on the farm, type of personal protective equipment (PPE) use, as well as duration and frequency of exposure. Four candidate renal biomarkers including π-GST, sirtuin-1, mitochondrial DNA (mtDNA) were measured. Most subjects were male and mostly sprayed three herbicides including glyphosate-based herbicides (GBH), paraquat, and 2,4-dichlorophenoxyacetic acid (2,4-D). A type of activity in farm was mixing and spraying herbicide. Our finding demonstrated no statistical significance of all biomarker levels between pre- and post-work task urine. To compare between single and cocktail use of herbicide, there was no statistical difference in all biomarker levels between pre- and post-work task urine. However, the urinary mtDNA seems to be increased in post-work task urine. Moreover, the cumulative EII was strongly associated with change in mtDNA content in both ND-1 and COX-3 gene. The possibility of urinary mtDNA as a valuable biomarker was promising as a noninvasive benchmark for early detection of the risk of developing renal injury from herbicide exposure.

Factors associated with respiratory symptoms among herbicide applicators and assistant applicators in maize field.

A cross-sectional study was conducted with 3,291 maize farmers enrolled whose main roles were herbicide applicators and assistant applicators. This study aimed to compare the prevalence of respiratory symptoms and the use of personal protective equipment (PPE) between herbicide applicators and assistant applicators, and determine factors associated with respiratory symptoms. Our results suggest that wheeze and dyspnea were associated with the task on the farm (adj. OR = 10.33 for wheeze and 24.13 for dyspnea), amount of herbicide use (adj. OR = 1.95 for wheeze and 1.41 for dyspnea), frequency of herbicide use (adj. OR = 2.87 for wheeze and 4.08 for dyspnea), not always wearing a mask (adj. OR = 1.49 for wheeze and 3.17 for dyspnea), not always wearing gloves (adj. OR = 2.63 for wheeze and 2.44 for dyspnea), and not always wearing goggles (adj.OR = 2.01 for dyspnea) after adjusting for confounding factors.

Composition and Acute Inflammatory Response from Tetraponera rufonigra Venom on RAW 264.7 Macrophage Cells.

Tetraponera rufonigra (Arboreal Bicoloured Ant) venom induces pain, inflammation, and anaphylaxis in people and has an increased incident in Southeast Asia regions. The bioactive components and mechanism of action of the ant venom are still limited. The aim of this research was to identify the protein composition and inflammatory process of the ant venom by using RAW 264.7 macrophage cells. The major venom proteins are composed of 5' nucleotidase, prolyl endopeptidase-like, aminopeptidase N, trypsin-3, venom protein, and phospholipase A2 (PLA2). The venom showed PLA2 activity and represented 0.46 µg of PLA2 bee venom equivalent/µg crude venom protein. The venom induced cytotoxic in a dose- and time-dependent manner with IC20 approximately at 4.01 µg/mL. The increased levels of COX-2 and PGE2 were observed after 1 h of treatment correlating with an upregulation of COX-2 expression. Moreover, the level of mPGES-1 expression was obviously increased after 12 h of venom induction. Hence, our results suggested that the induction of COX-2/mPGEs-1 pathway could be a direct pathway for the ant venom-induced inflammation.

Effect of Occupational Exposure to Herbicides on Oxidative Stress in Sprayers.

BACKGROUND: Herbicides such as glyphosate, paraquat, and 2,4-dichlorophenoxyacetic acid have been reported to cause adverse side effects through production of reactive oxygen species. However, there were no data representing the adverse effects of a mixture herbicide usage in farmers, especially the changes in oxidative marker and antioxidant defense. This study aimed to determine the urinary malondialdehyde (MDA) and glutathione (GSH) level in farmers using mixed herbicides. METHODS: Ninety-three farmers were recruited, and two spot urine samples (before and after work) were collected. The urinary MDA level was evaluated by thiobarbituric acid reactive substance assay, and the urinary GSH level was determined using the enzymatic recycling method. RESULTS: Sixty-two percent of the participants were men, and 59% of the participants worked in a farm for 20-40 years. The common combinations of herbicide usage were glyphosate with 2,4-dichlorophenoxyacetic acid (36.5%). There was no significant difference between pre- and post-work urinary MDA and GSH levels among the 3 groups of herbicides. However, the urinary MDA levels in farmers using the combination of glyphosate and paraquat were significantly higher than those found in farmers using glyphosate alone. The associated factors with changes in MDA levels found that the exposure intensity index (B = 0.154), the cumulative exposure intensity index (B = 0.023), and wearing gloves while working (B = -2.347) were found to be significantly associated with MDA level. CONCLUSION: The results suggest that the combined use of glyphosate and paraquat caused a significant increase in urinary MDA levels. Moreover, intensity of exposure to herbicide and wearing gloves were associated with the level of MDA.

Genetic analysis of 12 X-short tandem repeats loci in a northern Thai population.

Short tandem repeats (STRs) are widely used as DNA markers in paternity testing and criminal investigations because of their high genetic polymorphism among individuals in population. However, many factors influence genetic variations of STRs. Therefore, understanding STR information within individual populations could provide database and scientifically reliable STR genotyping for forensic genetic purposes. We aimed to examine allele frequencies of X-STRs, including some forensic parameters, in a northern Thai population. A retrospective descriptive study was conducted by collecting X-STR data from unrelated individuals living in a northern region of Thailand. The allele frequency and forensic parameters - for example polymorphism information content (PIC), power of discrimination in females and males (PDf and PDm), mean exclusion chance (MEC) and haplotype frequency - were calculated. The Hardy-Weinberg equilibrium was analysed. A total of 132 alleles were observed, with corresponding allele frequency ranging from 0.0064 to 0.4904. The PIC of all loci was >0.6, representing high genetic polymorphism, except DXS8378 and DXS7423. Notably, DXS10135 was the most diverse loci with the highest PD and MEC, while DXS7423 was the least polymorphic marker with the lowest PD and MEC. The highest haplotype diversity in male data was on linkage group III (DXS10101-DXS10103-HPRTB) by 0.9895. The genetic distance analysis demonstrated that the northern Thai population had a close relationship with Taiwanese (DA = 0.023). There are no significant deviations among the Hardy-Weinberg equilibrium except DXS10148. This study has established a northern Thai X-STRs reference database to be used as a tool for forensic genetic purposes.

A suitable biomarker of effect, club cell protein 16, from crystalline silica exposure among Thai stone-carving workers.

Exposure to respirable crystalline silica (RCS) reportedly induces chronic lung injury. We investigated the association between RCS exposure and two biomarkers of the effect, plasma club cell protein 16 (CC16) and heme oxygenase-1 (HO-1) levels, in stone-carving workers. Fifty-seven exposed workers (EWs) and 20 unexposed workers (UWs) were enrolled onto the study. Cumulative exposure to RCS was individually estimated using a filter-based gravimetric method. The plasma CC16 and HO-1 levels were determined using commercial kits. The 8-h time-weighted average for RCS concentration in the EW was significantly greater than this concentration in the UW (p < 0.001). The health risk characterization for RCS exposure expressed as a hazard quotient (HQ) indicated that crystalline silica might be a risk factor where there is chronic exposure (HQ = 4.48). The EW group presented a significant decrease in CC16 and an increase in HO-1 levels in comparison to the UW group (p < 0.001). In addition, we found a significant association between RCS concentration and plasma CC16 only. Therefore, our findings representing a significant decrease in CC16 in the plasma of stone-carving workers and this biological marker were significantly associated with RCS concentration. Our data indicated that CC16 might be a suitable biomarker to use to predict the health risk to stone-carving workers of exposure to RCS.

Urinary organophosphate metabolites and oxidative stress in children living in agricultural and urban communities.

Exposure to organophosphate (OP) pesticides in children may increase oxidative stress, resulting in the development of chronic diseases. This study aims to compare urinary OP metabolites and oxidative stress between children in agricultural and urban communities. The study also investigated the factors associated with urinary OP metabolites among children. Urine samples were collected from children for measuring levels of OP metabolites, glutathione (GSH), and malondialdehyde (MDA). The remarkable findings were that total dialkylphosphate (DAP) levels detected among children in this agricultural community were significantly higher than those from the urban community (P = 0.001). Multiple linear regression showed that total diethylphosphate (DEP) levels among children in the agricultural community were negatively associated with distances from children's residence to the agricultural fields (ß ± SE. = - 1.535 ± 0.334, 95%CI = - 2.202, - 0.863) and positively associated with playing on farms (ß ± SE. = 0.720 ± 0.342, 95%CI = 0.036, 1.405). In addition, total dimethylphosphate (DMP) levels were positively associated with children working on farms (ß ± SE. = 0.619 ± 0.264, 95%CI = 0.091, 1.147). Importantly, GSH levels among children in the agricultural community were significantly lower than those in the urban community (P < 0.001), but MDA levels did not differ. These results therefore suggest that children can be exposed to OPs both outdoors and indoors. Our results also provide supporting evidence that OP exposure can cause oxidative stress in children. As oxidative stress contributes to several chronic diseases, a good proposed strategy for the future would include measurement of oxidative stress biomarkers among children exposed to OPs as an early warning of chronic diseases.

Biological variation in kidney injury and kidney function biomarkers among farmers in Lamphun province, Thailand.

Frequent and long-term exposure to pesticides can induce acute kidney injury and subsequent chronic kidney diseases. In this study, we aimed to investigate the correlation between kidney injury, kidney function biomarkers, and pesticide use in farmers from the Pasang district, Lamphun province, Thailand. A cross-sectional study was performed in 59 farmers occupationally exposed to various types of pesticides. The levels of urinary neutrophil gelatinase-associated lipocalin (uNGAL), serum creatinine (sCr), urinary microalbumin-to-creatinine ratio (ACR), serum cystatin C (sCys-C), estimated glomerular filtration rate (eGFR), and exposure intensity index (EII) were evaluated. Spearman's correlation and a linear regression analysis were carried out to investigate the association between age, pesticide use, EII, kidney injury markers, and kidney function biomarkers. The most common pesticide used in this study area was glyphosate, followed by paraquat and iprodione. Urinary NGAL levels showed a significant correlation with sCys-C levels, EII, and eGFR Cr-Cys. In addition, the sCr levels were associated with glyphosate use (B = 0.08) and EII (B = 0.01). In conclusion, occupation exposure to pesticides is likely to be linked to kidney injury and dysfunction. Pesticide mix status, pesticide application method, equipment repair status, and personal protective equipment (PPE) use are all involved in changes in kidney markers.

Changes in lung function and respiratory symptoms during pesticide spraying season among male sprayers.

Exposure to pesticides via inhalation might impair lung function and develop further severe respiratory symptoms and diseases. Thus, the purpose of the study was to compare lung function between pre- and post-pesticide spraying seasons among male sprayers. The study also evaluated the association of lung function changes and other factors with respiratory symptoms. The follow-up study was conducted on 58 male sprayers. The subjects were interviewed and measured lung function before and after pesticide spraying season. The results found that forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and peak expiratory flow rate in the post-spraying season were significantly lower than in the pre-spraying season. With regard to respiratory symptoms, cough symptoms were associated with changes in FEV1/FVC [odd ratio (OR) = 1.29, 95% confidence interval (CI) = 1.01-1.67)] and smoking status (OR = 12.95, 95%CI = 1.35-124.34). Phlegm symptoms were also associated with changes in FVC (OR = 2.07, 95%CI = 1.01-4.25) and FEV1 (OR = 0.41, 95%CI = 0.18-0.91). The study provides evidence that pesticide spraying may increase risks for significant alteration of lung function and respiratory symptoms.

A longitudinal follow-up study of oxidative stress and DNA damage among farmers exposed to pesticide mixtures.

Exposure to pesticides may have increased risk of oxidative stress and genetic damage and hence of development of chronic diseases. The aim of this longitudinal follow-up study is to compare oxidative stress and DNA damage between the pre- and post-pesticide application seasons among 56 male farmers. The study also investigated the factors associated with changes in oxidative stress, DNA damage, and health symptoms during the pesticide application season. The eligibility criteria for the subjects were men aged between 25 and 55 years, applied pesticide mixtures during May and June 2018, and healthy without current illness. Ten milliliters of venous blood samples was collected twice from each subject in the pre- and post-pesticide application seasons for determination of superoxide dismutase (SOD), 8-hydroxy-2'-deoxyguanosine (8-OHdG), comet tail length, and comet tail moment. The remarkable findings included a statistically significant increase in SOD activity during the pesticide application season (P < 0.001). However, there were no statistical differences in 8-OHdG, comet tail length, and comet tail moment. When we analyzed the factors associated with changes in SOD activity during the pesticide application season by using linear regression analysis, working hours on the farm (B ± SE. = 0.790 ± 0.341, P = 0.025) and planting activities (B ± SE. = 1.217 ± 0.504, P = 0.020) were associated with increase in SOD activity. Therefore, increase in SOD may be a consequence of oxidative damage induced by pesticide exposure and this marker may be used as an early warning for pesticide-induced acute and chronic toxicities.

A potential of propolis on major virulence factors of Cryptococcus neoformans.

The present study was conducted to investigate the effects of a natural product from honeybees, named propolis, against Cryptococcus neoformans and its effect in the expression of putative virulence factors, such as capsular polysaccharides, melanin production and urease enzyme. Ethanol extract propolis (EEP) was first tested for its anti-cryptococcal activity and explored its impact on virulence factors in both phenotypes and enzyme activities. Moreover, the cryptococcal virulence genes were investigated using real time RT-PCR. The MIC value of EEP, 1 mg ml-1, displayed potent inhibition of C. neoformans cell viability. Of note is the high efficacy of sub-MIC concentrations (ranging from 0.5 to 0.125 mg ml-1) in decreasing the production of capsule, melanin, as well as laccase and urease enzyme activities. Importantly, EEP exhibited statistically decrease in the expression of gene-encoded virulence factors. In conclusion, EEP mediates C. neoformans growth inhibition and virulence factors by reducing the gene-encoding virulence-associated proteins and, thereby, disrupting the morphologic presence and attenuating their virulence. This study introduced EEP as regards anti-cryptococcal virulence factors activities; therefore, EEP would provide alternative ways of controlling the pathogenicity.

Propolis extracts from the northern region of Thailand suppress cancer cell growth through induction of apoptosis pathways.

The continual increase in mortality rates and number of cancer cases is a matter of serious concern in developing countries. The incorporation of natural products into classical cancer treatment approaches is a promising direction. The mechanisms of A549 and HeLa cancer cell death induction by ethanolic extracts of propolis samples from Phayao, Chiang Mai, and Nan provinces in northern Thailand were investigated in this study. The propolis extract from Chiang Mai showed the highest antioxidant activity and the greatest total phenolic content. The propolis extract from Nan also exhibited the highest total flavonoid content. The proliferation of A549 and HeLa cells grown in the presence of the propolis extracts was suppressed in a dose- and time-dependent manner. Moreover, treatment of both cancer cells with the propolis extracts showed DNA fragmentation and significantly increased the number of the apoptotic cells. On A549 cells, the extrinsic and intrinsic pathways of caspase enzymes were activated by the propolis extracts from Phayao and Chiang Mai. In the case of the propolis extract from Nan, the mechanisms involved apoptosis on the A549 cells were caspase-independent pathway. The extrinsic pathway of the caspase enzyme was triggered by all of the propolis extracts on HeLa cells. Finally, oral administration of the propolis granule produced from the propolis extract from Nan resulted in extended survival of tumour-bearing mice. Therefore, propolis extracts from the northern region of Thailand demonstrated pharmacological properties, both antioxidant and anticancer activities. From these findings, it is evident that propolis extracts can be considered as a naturally obtained agent extremely useful in cancer treatment.

Antioxidant and anti-cancer cell proliferation activity of propolis extracts from two extraction methods.

Antioxidant activity, total phenolic, total flavonoid compounds and cytotoxicity to cancer cell lines of propolis extracts from two extraction methods were investigated in this study. Propolis was collected from Phayao province and extracted with 70% ethanol using maceration and sonication techniques. The antioxidant activity was evaluated by DPPH assay. Total phenolic and flavonoid compounds were also determined. Moreover, the cytotoxicity of propolis was evaluated using MTT assay. The percentage propolis yield after extraction using maceration (18.1%) was higher than using sonication (15.7%). Nevertheless, antioxidant and flavonoid compounds of the sonication propolis extract were significant greater than using maceration. Propolis extract from sonication showed antioxidant activity by 3.30 ± 0.15 mg gallic acid equivalents/g extract. Total phenolic compound was 18.3 ± 3.30 mg gallic acid equivalents/g extract and flavonoid compound was 20.49 ± 0.62 mg quercetin/g extract. Additionally, propolis extracts from two extraction methods demonstrated the inhibitory effect on proliferation of A549 and HeLa cancer cell lines at 24, 48 and 72 hours in a dose-dependent manner. These results are of interest for the selection of the most appropriate method for preparation of propolis extracts as potential antioxidant and anticancer agents.