Search Results (84)

Northern Thailand frequently suffers from severe PM2.5 air pollution, especially during the dry season, due to agricultural burning, local emissions, and transboundary haze. Understanding how pollution moves across regions and identifying source–receptor relationships are critical for effective air quality management. This study investigated the spatial and temporal dynamics of PM2.5 in northern Thailand. Specifically, it explored how pollution at one monitoring station influenced concentrations at others and revealed the seasonal structure of PM2.5 transmission using network-based analysis. We developed a Python-based framework to analyze daily PM2.5 data from 2022 to 2023, selecting nine representative stations across eight provinces based on spatial clustering and shape-based criteria. Delaunay triangulation was used to define spatial connections among stations, capturing the region’s irregular geography. Cross-correlation and Granger causality were applied to identify time-lagged relationships between stations for each season. Trophic coherence analysis was used to evaluate the hierarchical structure and seasonal stability of the resulting networks. The analysis revealed seasonal patterns of PM2.5 transmission, with certain stations, particularly in Chiang Mai and Lampang, consistently acting as source nodes. Provinces such as Phayao and Phrae were frequently identified as receptors, especially during the winter and rainy seasons. Trophic coherence varied by season, with the winter network showing the highest coherence, indicating a more hierarchical but less stable structure. The rainy season exhibited the lowest coherence, reflecting greater structural stability. PM2.5 spreads through structured, seasonal pathways in northern Thailand. Network patterns vary significantly across seasons, highlighting the need for adaptive air quality strategies. This framework can help identify influential monitoring stations for early warning and support more targeted, season-specific air quality management strategies in northern Thailand. Full article

Urbanization, escalating agriculture, tourism, and industrial development in the Chiang Mai–Lamphun groundwater basin in northern Thailand have increased water demand, causing widespread groundwater extraction. Over the past few decades, there has been a rapid, unrecoverable steady drop in groundwater levels in several areas in Chiang Mai and Lamphun provinces. This study employed hydrogeological investigations, hydrometeorological data analyses, stable isotopic analysis (δ¹⁸O and δ²H), and groundwater flow modeling using a 3D groundwater flow model (MODFLOW) to quantify groundwater recharge and delineate important groundwater recharge zones within the basin. The results showed that floodplain deposits exhibited the highest recharge rate, 104.4 mm/y, due to their proximity to rivers and high infiltration capacity. In contrast, younger terrain deposits, covering the largest area of 1314 km², contributed the most to total recharge volume with an average recharge rate of 99.8 mm/y. Seven significant recharge zones within the basin, where annual recharge rates exceeded 105 mm/y (average recharge of the entire basin), were also delineated. Zone 4, covering parts of densely populated Muaeng Lamphun, Ban Thi, and Saraphi districts, had the largest area of 330 km² and a recharge rate of 130.2 mm/y. Zone 6, encompassing Wiang Nong Long, Bai Hong, and Pa Sang districts, exhibited the highest recharge rate of 134.6 mm/y but covered a smaller area of 67 km². Stable isotopic data verified that recent precipitation predominantly recharged shallow groundwater, with minimal evaporation or isotopic exchange. The basin-wide average recharge rate was 104 mm/y, reflecting the combined influence of geology, permeability, and spatial distribution. These findings provide critical insights for sustainable groundwater management in the region, particularly in the context of climate change and increasing water demand. Full article

This study examines how seasonal air pollution affects health perceptions, risk awareness, and preventive behaviors among a sample of 150 individuals, particularly within vulnerable people living in Thailand. Many participants were older adults (54.7% aged ≥ 60), female (76.7%), and had a low income (less than 10,000 THB/month (USD 295), 92.6%). Polycyclic Aromatic Hydrocarbon (PAH) exposure, as indicated by urinary 1-Hydroxypyrene (1-OHP), significantly increased during high-pollution periods (p < 0.001), while benzo[a]pyrene diol epoxide (BPDE) levels did not show significant changes. Farmers exhibited the highest PAH exposure (p = 0.018). Risk perception and preventive behavior scores rose from 0.711 to 0.748 and from 0.505 to 0.707, respectively. Notable items with high factor loadings included “burning pollutes the air and spreads pollution” (Q2.1 = 0.998) and “avoid burning of any kind” (Q4.2 = 1.007). Neurological symptoms, such as loss of consciousness, increased from 0.956 to 1.049, while respiratory problems like pneumonia went up from 0.673 to 1.07. Environmental risk knowledge-related perceptions experienced a slight decline (from 0.609 to 0.576). These results highlight the need for targeted education through community workshops and strategies like mask distribution, indoor air filtration, and early warning systems for vulnerable populations. Full article

This study develops a value-added processing technique for grade-out cape gooseberry (Physalis peruviana Linn.) by applying mild hydrostatic osmotic pretreatment combined with rotary tray drying. Fruits classified as grade-out, often discarded due to aesthetic flaws, were subjected to osmotic treatment at 0.5 bar for 12 h using a sucrose solution enhanced with citric acid and glycerin. Pretreatment significantly elevated water loss (52.61%) and solid gain (18.12%), reducing moisture content prior to drying. Rotary tray drying was conducted at temperatures of 50, 60, and 70 °C. Drying at 60 °C achieved the ideal balance between efficiency and product quality. Samples pretreated and dried at 60 °C exhibited a 35% reduction in drying time while preserving superior color (ΔE = 13.54 ± 1.81), vitamin C (71.76 ± 2.57 mg/100 g dry matter, DM), total phenolic content (202.9 ± 10.91 mg GAE/100 g DM), and antioxidant activity (ABTS = 95.87 ± 3.41 µmol TE/g DM; DPPH = 89.97 ± 1.27 µmol TE/g DM). A production trial was conducted using 1500 kg of raw material from the Mae Hae Royal Project Development Center in Chiang Mai, Thailand. This process yielded 220 kg of high-quality dried fruit at an overall cost of USD 6.93 per kg. Local farmers successfully applied this technique, demonstrating its potential to enhance livelihoods, avoid postharvest losses, and valorize low-quality produce in line with Sustainable Development Goal 12. This supports the Royal Project Foundation’s vision for sustainable agriculture. Full article

The present study investigated the concentrations, sources, and potential health risk assessment of polycyclic aromatic hydrocarbons (PAHs) in house dust from residences in Samoeng District, Chiang Mai Province, Thailand. Samples of house dust from 48 households were analyzed for 16 PAHs. The total concentrations of PAHs (ΣPAHs) ranged between 270.1 to 45,386.8 ng g⁻¹, with a mean of 3942.4 ± 8175.1 ng g⁻¹. Pyrene (Pyr), benzo(k)fluoranthene (BkF), and indeno(1,2,3-cd)pyrene (IcdP) were the predominant compounds. Diagnostic ratios and principal component analysis (PCA) showed wood and the burning of biomass as the predominant sources. Evaluations of incremental lifetime cancer risk (ILCR) showed higher risks, especially for children (average ILCR = 6.57 × 10⁻³), with dermal contact as the main exposed pathway. Risks exceeded acceptable criteria (10⁻⁶ to 10⁻⁴), suggesting serious public health problems. The results highlight the significance of pollution mitigation measures, such as reducing the use of biomass combustion and improving indoor air quality, for protecting vulnerable populations in rural regions. The research conducted presents important insights into the environmental health impacts of PAHs in residences and shows the importance of public health procedures that can reduce exposure. Full article

Historically, natural pigments have been used to color textiles, food, and cosmetics, but the rise of synthetic dyes in the 19th century reduced their use. Recently, interest in plant-based pigments has surged due to health and environmental concerns. Among Thailand’s ethnic groups, the Karen use plant colorants extensively, but their practices remain understudied. In this study, we document the knowledge of plant colorants of the Karen community in Chiang Mai province, assess the color stability of the plant colorants, and evaluate their cytotoxicity in HepG2 cells. Interviews with 113 informants revealed 52 plant species used for dyeing, primarily through hot water extraction. The most common color was brown, and Strobilanthes cusia had the highest color use value (0.93). The study identified 10 color shades, with blue showing the highest consensus. Color stability was tested at room and elevated temperatures, which showed that colorants from Oroxylum indicum were the most stable, and those of Strobilanthes cusia had the lowest toxicity (CC₅₀ = 994.1 µg/mL), while Artocarpus lacucha had the highest toxicity (CC₅₀ = 63.96 µg/mL). Oroxylum indicum, which has excellent color stability and moderate cytotoxicity (CC₅₀ = 294.4 µg/mL), is recommended as a promising natural colorant. This study provides valuable insights into preserving traditional knowledge in Karen communities. Full article

This study employs a dual methodological approach, integrating Google Earth Engine (GEE) and unsupervised classification (UNSUP) to analyze urban expansion patterns in Chiang Mai province using nighttime light imagery. The research utilizes Visible Infrared Imaging Radiometer Suite (VIIRS) satellite data from 2014 to 2023 to assess urban growth dynamics. The primary objectives are to (1) evaluate the performance of GEE and UNSUP in nighttime light data processing, (2) validate urban area classification accuracy using multiple assessment metrics, and (3) examine the relationship between nighttime light intensity and electricity consumption through Pearson’s correlation analysis, thereby establishing urban growth patterns. The methodological framework incorporates a dual-threshold classification mechanism in GEE and K-means clustering in traditional geospatial software. Accuracy assessment is conducted using 256 stratified random sampling points, complemented by land use and land cover (LULC) data for ground truth validation. The results indicate that GEE consistently outperforms UNSUP, achieving overall accuracy values between 0.80 and 0.82, compared to 0.73 and 0.76 for UNSUP. The Kappa coefficient for GEE ranges from 0.60 to 0.65, whereas UNSUP demonstrates lower agreement with ground truth data (0.44–0.52). Furthermore, both approaches reveal a significant correlation between electricity consumption and nighttime light intensity, with R² = 0.9744 for GEE and R² = 0.9759 for UNSUP, confirming the efficacy of nocturnal illumination data in urban expansion monitoring. The findings indicate that urban areas in Chiang Mai have expanded by approximately 70% over the study period. This research contributes to the field by demonstrating the effectiveness of integrated geospatial methodologies in urban development analysis. The findings offer urban planners and policymakers critical insights for sustainable urban growth management and decision-making. Full article

Background: This study aimed to explore the relationship between architectural home design and mental health in older adults living independently in rural Chiang Mai. Methods: A purposive sample of seniors from San Kamphaeng District, living independently, were selected. Participants were assessed using tools like the MSPSS, OI-21, RULS-6, RI-9, PSQI, and a custom Home and Community Environment Satisfaction Scale. Statistical analysis examined correlations between home design, mental health, and satisfaction. Results: The study involved 83 participants (72.3% female, mean age 70.2 ± 6.16). Anxiety (3.51 ± 3.44) and depression (2.69 ± 3.19) levels were low, with minimal loneliness (10.02 ± 3.92). Social support was moderate (63.11 ± 15.69), and resilience was strong (38.42 ± 6.43). Nearly half of the participants (48.2%) had poor sleep quality. Architectural features influenced mental health, with larger yard spaces improving social support, while gardens had a negative correlation due to maintenance. Single-story homes with accessible layouts and south/east-facing living rooms improved mental health. Larger doors were linked to poorer sleep quality. Conclusions: Positive architectural designs, including accessible bedrooms and favorable orientations, enhance mental health for the elderly, supporting aging in place. Full article

The incidence of hypertension (HT) is rapidly increasing globally, and it is considered to be a critical public health problem. Due to the demand for medication and because various side effects of anti-hypertensive drugs have been reported, complementary and alternative therapies, including Thai Indigenous medicine (TIM), should be explored for treating HT. Medicinal plants traditionally used by multiple cultures over long time periods in HT treatment are more likely to be pharmacologically active and might provide useful data, leading to anti-hypertensive drug discovery. Ethnomedicinal field observations were undertaken with 41 key informants in eleven villages in Chiang Mai province from December 2022 to November 2023. In addition, we gathered data on traditional plants used for treating HT among 12 ethnic groups from 41 original references published between 1987 and 2023, covering nine provinces in northern Thailand. Important species among plants used for treating hypertension were identified by calculating their relative frequency of citation (RFC). In total, we found 237 plant species that were used for treating HT. Of these, 173 species had already been reported in the literature, and 96 species were documented in our fieldwork. There were 30 plant species from our field survey that overlapped with species accounted for in the literature. Fabaceae was the plant family with the most species (23 sp, 10%) used for treating HT. The most commonly used species was Blumea balsamifera (L.) DC. (Asteraceae), and it had the highest recorded RFC value of 0.1979. There were 64 plant species that were reported for the first time for HT treatment among ethnic groups in northern Thailand. Of the recorded species, 24 were particularly promising in the treatment of HT, and their efficacy was confirmed by comparing our results to previous studies of plants with anti-hypertensive properties. Full article

Mafic and ultramafic rocks have become a promising approach for atmospheric carbon dioxide (CO₂) reduction, as they are major sources of CO₂-reactive minerals, i.e., olivine, pyroxene, plagioclase, and serpentine. The minerals potentially sequester CO₂ by turning it into a stable solid phase through carbon mineralization in the rock weathering process. However, detailed descriptions and evaluations of the target formations are lacking. This study investigates the mineralogical composition and microtextural characteristics of representative mafic and ultramafic rocks observed in northern Thailand, using a petrographic analysis. The results show that variations in CO₂-reactive mineral assemblages of rocks certainly affect their theoretical CO₂ uptake potential. Ultramafic rocks tend to sequester larger amounts of CO₂ than mafic rocks. The microtextural observation reveals the mineral size ranges of 0.05–5 mm for ultramafic and mafic intrusive rocks and 0.01–2 mm for mafic extrusive and metamorphosed rocks. Reducing the rock size to be equal to the average size of the reactive minerals could be considered one of the practical designs in enhanced rock weathering activities. Understanding the mineralogical and textural characteristics of target rocks thus plays a crucial role in further georesource exploration and engineering designs, supporting climate action strategies on various scales. Full article

For the success of efficient socioeconomic development, it is crucial that budget allocation in higher education is effectively managed, with a clear focus on targeting SDG 4 (Quality Education), which is vital for every country and should be prioritized globally. This research article attempts to assess the socio-economic impact of Chiang Mai University based on the impact of both its expenditure and teaching and training programs on the Northern Thailand economy. Moreover, it also aims to develop the best model to predict the SROI for academic projects before investing the budget for efficient financial management. All the data utilized in this research article come from official organizations such as Chiang Mai University, the Office of the National Economic and Social Development Council (NESDC), and the Provincial Comptroller’s Office of each province in Northern Thailand, with the data collection covering the study period from 2023 to 2025. The key finding is that Chiang Mai University played a significant role in creating a socioeconomic impact on Northern Thailand’s economy, both in the industry sector and the service sector, totaling more than an average of THB 3 billion per year for direct and indirect effects. In addition, every THB 1 million that this university spends can create more than 703 jobs in the agribusiness sector, and, for the same budget spending, it can create 241 jobs in the service sector and 113 jobs in the industry sector, respectively. Technically, for the prediction model to predict the SROI value, it was found that the best model is the Decision Tree model. If the findings of this research can be applied to other universities in Thailand or globally, it would represent a significant initiative in optimizing budget allocation, with a particular emphasis on supporting SDG 4 (Quality Education) as a priority. Full article

Based on a soil analysis of individual crops, lower nitrogen (N) inputs may affect soil fertility and the soil’s capacity for carbon sequestration. This study investigates the changes in soil nitrogen levels, the amounts of labile and recalcitrant carbon fractions, and their relationship to soil organic carbon (SOC) over the course of a single crop season. We conducted this study on seven crops in the provinces of Chiang Mai, Lamphun, and Lampang in northern Thailand, from February 2022 to December 2023. The farmer plots, which included litchi, mango, banana, maize, cabbage, garlic, and paddy rice, underwent three nitrogen addition treatments: high-nitrogen fertilizer (FP), reduced-nitrogen fertilizer informed via soil analysis (FS), and fertilizer absence (FZ). Soil samples were collected from a depth of 0 to 30 cm following the harvest of each crop. Subsequently, we utilized these samples to distinguish between labile and recalcitrant carbon fractions and assessed the impact of reduction through a one-way ANOVA. This study indicated a reduced availability of nitrogen, with the recalcitrant carbon fractions being the fine fraction (FF) and less labile carbon (LLB_C). The labile organic carbon fraction, referred to as LB_C, exhibited no change in FP treatment, in contrast to the non-fine fraction (NFF) and permanganate-oxidizable carbon (POXC). Our concern was to reduce the quantity of synthetic nitrogen fertilizer to achieve a lower level of soil organic carbon (SOC) and decreased nitrogen availability. These findings underscore the importance of considering N management when assessing soil carbon dynamics in agricultural soils, and, in future work, we should therefore model the optimal N input for crop yield, soil fertility, and soil carbon storage. Full article

This study introduces Curcuma borealis Saensouk, P.Saensouk, and Boonma and C. retrocalcaria Saensouk, P.Saensouk, and Boonma, two newly discovered species within the Curcuma genus of the Zingiberaceae family, found in the Mae Hong Son and Chiang Mai Provinces of Northern Thailand, respectively. This research aims to clarify the taxonomic identity of these species, which were initially confused with C. ecomata Craib and C. chantaranothaii Boonma and Saensouk due to similarities in flower coloration and some morphological characteristics, respectively. Detailed morphological analysis was conducted to distinguish these species. Curcuma borealis is differentiated by its unique anthers lacking appendages or projections at the base of the spurs, in contrast to the appendages or projections present in C. ecomata, while C. retrocalcaria is characterized by anther spurs folding or curving backward under the anther base and with two purple patches at the base of the labellum, distinguishing it from C. chantaranothaii. The findings highlight distinct morphological traits that set C. borealis and C. retrocalcaria apart from existing Curcuma species. The pollen morphology of the two new taxa was also studied here for the first time. This research emphasizes the importance of thorough taxonomic scrutiny for accurate species identification and contributes to our understanding of the diversity within the Curcuma genus. Accurate identification of these species is crucial for conservation efforts, underscoring the need to protect their habitats and maintain biodiversity in the region. Full article

Air pollution, particularly PM2.5, poses a significant environmental and public health concern, particularly in northern Thailand, where elevated PM2.5 levels are prevalent during the dry season (January–May). This study examines the influx and patterns of transboundary biomass burning PM2.5 (TB PM2.5) in this region during the 2019 dry season using the WRF-Chem model. The model’s reliability was confirmed through substantial correlations between model outputs and observations from the Pollution Control Department (PCD) of Thailand at 10 monitoring stations. The findings indicate that TB PM2.5 significantly influences local PM2.5 levels, often surpassing contributions from local sources. The influx of TB PM2.5 began in January from southern directions, intensifying and shifting northward, peaking in March with the highest TB PM2.5 proportions. Elevated levels persisted through April and declined in May. Border provinces consistently exhibited higher TB PM2.5 concentrations, with Chiang Rai province showing the highest average proportion, reaching up to 45%. On days when PM2.5 levels were classified as ‘Unhealthy for Sensitive Groups’ or ‘Unhealthy’, TB PM2.5 contributed at least 50% to the total PM2.5 at all stations. Notably, stations in Chiang Rai and Nan showed detectable TB PM2.5 even at ‘Very Unhealthy’ levels, underscoring the significant impact of TB PM2.5 in the northern border areas. Effective mitigation of PM2.5-related health risks requires addressing PM2.5 sources both within and beyond Thailand’s borders. Full article

Chiang Mai province of Thailand is known for having the highest natural background radiation in the country, as well as being recognized as one of the world’s most polluted cities for air quality. This represents the major contributor to the development of lung cancer. This research aims to estimate the comprehensive dose of both internal and external exposure due to natural background radiation and related health perspectives in the highly polluted area of Chiang Mai. The average values of indoor radon and thoron concentrations in 99 houses over 6 months were 40.8 ± 22.6 and 17.8 ± 16.3 Bq/m³, respectively. These results exceed the worldwide value for indoor radon and thoron (40 and 10 Bq/m³), respectively. During burning season, the average values of indoor radon (56.7 ± 20 Bq/m³) and thoron (20.8 ± 20.4 Bq/m³) concentrations were higher than the world-wide averages. The radon concentration in drinking water (56 samples) varied from 0.1 to 91.9 Bq/L, with an average value of 9.1 ± 22.8 Bq/L. Most of the drinking water samples (87%) fell below the recommended maximum contamination limit of 11.1 Bq/L. The average values of natural radionuclide (²²⁶Ra, ²³²Th and ⁴⁰K) in 48 soil samples were 47 ± 20.9, 77.9 ± 29.7 and 700.1 ± 233 Bq/kg, respectively. All values were higher than the worldwide average of 35, 30 and 400 Bq/kg, respectively. The average value of outdoor absorbed gamma dose rate (98 ± 32.5 nGy/h) exceeded the worldwide average of 59 nGy/h. Meanwhile, the average activity concentrations of ²²⁶Ra, ²³²Th and ⁴⁰K in 25 plant food samples were 2.7 ± 0.1, 3.2 ± 1.6 and 1000.7 ± 1.9 Bq/kg, respectively. The ⁴⁰K concentration was the most predominant in plant foods. The highest concentrations of ²²⁶Ra, ²³²Th and ⁴⁰K were found in Chinese cabbage, celery and cilantro, respectively. The total annual effective dose for residents in the study area varied from 0.6 to 4.3 mSv, with an average value of 1.4 mSv. This indicates a significant long-term public health hazard due to natural background radiation and suggests a heightened radiation risk for the residents. The excess lifetime cancer risk value (5.4) associated with natural background radiation was found to be higher than the recommended value. Moreover, the number of lung cancer cases per year per million average of 25.2 per million persons per year was in the limit range 170–230 per million people. Overall, our results will be used for future decision making in the prevention of lung cancer risk associated with natural background radiation. Full article