Rainy Months Research Articles

Monitoring deposition and resuspension of the iron ore tailings in the Doce River after the Fundão Dam rupture

The Doce River, located in Southeast Brazil, is of great importance in supplying water for urban use, agriculture, fishing and other purposes. It was affected by a disaster that occurred on November 5, 2015 due to the collapse of the Fundão ore tailing dam, in the municipality of Mariana (MG). This disaster generated socio-environmental consequences, as some regions were severely affected due to the waste released in the river, which was considered potentially toxic in the short to long term. This work presents a temporal analysis of images from the Landsat 8 satellite, associating the aspects of rainfall in dry and rainy months, in years before and after the disaster (2014, 2015, 2016, and 2020), together with the Normalized Difference Water Index (NDWI) obtained by image digital processing, to analyze the relation between dry and rainy periods and the spectral response of images. This analysis allowed the understanding of the behavior of the suspended materials, before and after the disaster, to unravel how the dispersion of tailings occurs. Part of the ore tailing that was deposited along the river went into suspension again in the rainy season one year after the disaster and, five years after, the satellite images show no difference compared to pre-disaster conditions. But, seven years after the spill, there are still iron ore tailings deposited and mixed with the river sediments. The fluvial dynamics are incorporating the tailings into the sediments, originating conducive places to provide various types of metals adhered to the particulate matter. Keywords: iron ore tailings, rainfall, remote sensing.

Impact of extreme rainfall events on soil erosion in downstream Parnaíba River Basin, Brazilian Cerrado

This study investigates the impact of extreme rainfall events on soil erosion in the downstream Parnaíba River Basin, located in the Brazilian Cerrado. The analysis focused on rainfall erosivity (R factor) and soil erodibility (K factor) as key indicators. The average erosivity in the region was 9051 MJ mm h−1ha−1year−1, with a variation between 7943 and 10,081 MJ mm h−1ha−1year−1, suggesting a high erosive potential, mainly in the rainiest months, from December to April. The soils of the studied area, mainly Ultisols and Chernosols, present high to very high erodibility, with K factor values ranging from 0.025 to 0.050 t h MJ−1 mm−1. Furthermore, fieldwork revealed areas, near highways, with apparently fragile soils, as well as rills and gullies, identified through photographs taken during fieldwork. These locations, due to the combination of high erosivity and susceptible soils, were considered prone to the occurrence of erosion processes, representing an additional risk to local infrastructure. The spatialization of R and K factors, along with field observations, showed that much of the area is at high risk of erosion and landslides, particularly in regions with greater topographic variability and proximity to water bodies. These results provide a basis for the development of mitigation strategies, being important for the effective prevention of landslides.

Water Recovery of brine water treatment from a small-scale desalination system in Nakhon Ratchasima

This study aims to recover water from treating brine water of a small-scale desalination using a solar still. The design focuses on keeping temperatures inside at conditions suitable for water evaporation from the brine water basin. Water vapor rises and condenses into water droplets on the transparent glass cover, moving down the slope into a channel and collecting outside. The solar still is 1.0 m x 1.0 m x 0.5 m (width x depth x height) with a 25-degree slope for a transparent glass cover on top. This slope allows the water droplet to move down without reentering into the brine water basin below. The brine water was placed on top of the carbonized rice hull. The black residues can absorb heat energy by being a dark color, locally available, environmentally friendly, and stable. The test results during rainy and early winter months showed that the prototype solar still produced the average recovery water of 150 mL/day/set, with the hourly temperatures inside the chamber ranging from 30 to 70.1 Celsius. The highest inside temperature occurred at 2 PM, with an average of 70.1 Celsius. A correlation was observed between temperature and the amount of distilled water. Water recovery from the prototype ranged from 1,090 to 1,256 mL/day. Low recovery occurred in the rainy months. Estimation of water recovery rates in Nakhon Ratchasima ranged from 45 to 55 mL/m2/day. The solar still provides an alternative to recover water and mitigate the direct impact of brine water discharge from the small-scale desalination in Nakhon Ratchasima from possible effect of salinity water discharge. The method is economical, less burdensome to the caretaker, and low budget. The recovery water is freshwater; thus, it can be reused and has no long-term impact. The use of solar still is an auxiliary device that can be used with small-scale desalination in areas with saline water.

Prevalence and Genetic Diversity of Respiratory Syncytial Virus Reinfections in Young Thai Children, 2016-2023.

Although a vaccine for respiratory syncytial virus (RSV) is now available for pregnant women and the elderly, RSV remains a significant cause of respiratory illness in children globally. Reinfections by the same or different RSV subgroups in children residing in the tropics are currently under-studied. Therefore, we examined the patterns of RSV infection and reinfection in Thai children aged ≤ 5 years with respiratory symptoms from 2016 to 2023. Screening of 7710 pediatric respiratory specimens identified 1245 RSV-positive samples (16.1%), mostly from the rainy months (July-November). Interestingly, 74 children experienced two infections, and 6 had three infections. Reinfection by different RSV subgroups occurred in 30 children: 21 were initially infected with RSV-B and later with RSV-A, while 9 had the reverse pattern. Reinfections only by either RSV-A or RSV-B were observed in 22 and 2 children, respectively, with one child infected with RSV-A three times. All RSV-A reinfections belonged to the ON1 genotype, while RSV-B reinfections were BA9. Notably, reinfections across different seasons were observed within homologous pairs. These findings suggest a transitory immunity to natural RSV infection and provide the knowledge that may help optimize pediatric vaccination schedule. Ongoing epidemiological data on RSV are essential in monitoring genotype circulation and vaccine effectiveness.

The Influence of Relative Humidity and Pollution on the Meteorological Optical Range During Rainy and Dry Months in Mexico City

The Meteorological Optical Range (MOR) is a measurement of atmospheric visibility. Visibility impairment has been linked to increased aerosol levels in the air. This study conducted statistical analyses using meteorological, air pollutant concentration, and MOR data collected in Mexico City from August 2014 to December 2015 to determine the factors contributing to haze occurrence (periods when MOR < 10,000 m), defined using a light scatter sensor (PWS100). The outcomes revealed seasonal patterns in PM2.5 and relative humidity (RH) for haze occurrence along the year. PM2.5 levels during hazy periods in the dry season were higher compared to the wet season, aligning with periods of poor air quality (PM2.5 > 45 μg/m3). Pollutant-to-CO ratios suggested that secondary aerosols’ production, led by SO2 conversion to sulfate particles, mainly impacts haze occurrence during the dry season. Meanwhile, during the rainy season, the PWS100 registered haze events even with PM2.5 values close to 15 μg/m3 (considered good air quality). The broadened distribution of extinction efficiency during the wet period and its correlation with RH suggest that aerosol water vapor uptake significantly impacts visibility during this season. Therefore, attributing poor visibility strictly to poor air quality may not be appropriate for all times and locations.

Understanding tea plantation growth stages and cultural operations by synergy of optical and Synthetic Aperture Radar (SAR) indices

ABSTRACT Tea, as a key cash crop, demands year-round monitoring including the rainy months. Our study in Dehradun, Uttarakhand, India, leverages Synthetic Aperture Radar (SAR) data for its cloud-penetrating capabilities. Radar Vegetation Index (RVI) from Sentinel-1 and the Normalized Difference Vegetation Index (NDVI) from Sentinel-2 on the Google Earth Engine (GEE) platform was used. Results indicate that RVI can detect stages of tea plantation growth, even during the rainy season, while NDVI provides detailed insights into cultural operations, except rainy seasons. This method supports effective tea plantation monitoring and supply chain management across seasons.

Ground-Based MAX-DOAS Observations for Spatiotemporal Distribution and Transport of Atmospheric Water Vapor in Beijing

Understanding the spatiotemporal distribution and transport of atmospheric water vapor in urban areas is crucial for improving mesoscale models and weather and climate predictions. This study employs Multi-Axis Differential Optical Absorption Spectroscopy to monitor the dynamic distribution and transport flux of water vapor in Beijing within the tropospheric layer (0–4 km) from June 2021 to May 2022. The seasonal peaks in precipitable water occur in August, reaching 39.13 mm, with noticeable declines in winter. Water vapor was primarily distributed below 2.0 km and generally decreases with increasing altitude. The largest water vapor transport flux occurs in the southeast–northwest direction, whereas the smallest occurs in the southwest–northeast direction. The maximum flux, observed at about 1.2 km in the southeast–northwest direction during summer, reaches 31.77 g/m2/s (transported towards the southeast). Before continuous rainfall events, water vapor transport, originating primarily from the southeast, concentrates below 1 km. Backward trajectory analysis indicates that during the rainy months, there was a higher proportion of southeasterly winds, especially at lower altitudes, with air masses from the southeast at 500 m accounting for 69.11%. This study shows the capabilities of MAX-DOAS for remote sensing water vapor and offers data support for enhancing weather forecasting and understanding urban climatic dynamics.

Determining the Climate Type and Calculating the Drought Index during the Rainy Months for the Stations of Diwaniya, Samawa and Nasiriya in Southern Iraq

In this research, the climate type for the rainy months (January, February, March, April, May, October, November, December) was determined for three selected stations in southern Iraq (Diwaniyah, Samawah, Nasiriyah). By calculating the drought index for each of the rainy months mentioned above using Demarton's equation described in (Mohammed, 2020) Based on climate data including temperatures in Celsius and rainfall amounts for the above-mentioned stations for the period (2000-2021) which were obtained from the Iraqi General Commission for Meteorology and Seismic Monitoring. The results showed the mastery of arid and semi-arid climate in all study stations during most of the rainy months. Except for the months of December and January, where the climate is semi-humid in the stations of Nasiriyah and Diwaniyah, respectively. As for Samawah station, the climate is arid and semi-arid during all rainy months. The results of the statistical analysis using Excel program (2010) also showed a strong positive linear correlation between the values of the drought index and the amounts of rainfall during the rainy months at the stations (Diwaniya, Samawa, Nasiriya), where the values of the correlation coefficient reached (0.961, 0.953, 0.954) respectively. As for the linear correlation between the values of the drought index and the temperatures during the rainy months, the results showed a strong negative linear correlation between them, as the values of the correlation coefficient reached (-0.821, -0.836, -0.822) at the stations (Diwaniya, Samawa, Nasiriya) respectively.

Triple oxygen isotope variability of precipitation in a tropical mountainous region

We present one year of δD, δ18O, d-excess, and Δʹ17O data from monthly precipitation at a Caribbean coastal site in Panama and from tap waters across the country to constrain geographic, climate, and moisture source controls on isotopic variability and better understand the sources and mechanisms of precipitation in Central America, a region facing significant modifications to the annual rainfall cycle due to climate change. Monthly precipitation δD ranged from –52.2 to +14.3 ‰, δ18O from –7.6 to +0.4 ‰, d-excess from +7.1 to +11.6 ‰, and Δ′17O from +11 to +29 per meg. Rainy season precipitation samples were found to have lower δD, δ18O, and d-excess due to Rayleigh distillation during the condensation and rainout of Pacific moisture over the central cordilleras, which results in decoupling between d-excess and Δ′17O. Outlier Δ′17O values during peak dry and rainy months may reflect seasonal changes in water vapor sourcing, from Caribbean to Pacific and/or locally recycled moisture, or may be a result of organic contamination. Tap water δD ranged from –82.3 to –14.3 ‰, δ18O from –11.6 to –2.4 ‰, d-excess from +4.3 to +12.2 ‰ and Δ′17O from –2 to +84 per meg. Tap water δD and δ18O values increase eastward due to lower orographic effects and Pacific and locally recycled moisture contributions to rainfall and greater secondary evaporation. Tap water d-excess and Δ′17O values are also de-coupled but lack clear spatial trends and controls. The results of this study indicate the promise of adding Δ′17O to the isotopic toolkit in tropical mountainous regions with complicated water cycling dynamics and provide a baseline for future triple oxygen isotope investigations.

Enhancing Seed Access and Climate Resilience: A Farmer-Based Seed Multiplication Scheme in a Legume-Sorghum Double Cropping System in Mieso District Ethiopia

Sorghum is a major food security crop in Ethiopia. Sorghum landraces are particularly crucial in crop-livestock mixed farming systems in drylands, but due to the longer growing periods (6-8 months) needed for the landraces, the crop faces recurrent drought events associated with delayed rain, dry spells, and drought during critical stages. The landraces are normally grown combining a short and erratic rainy season (March to May) and a main rainy season (July to September). To address such circumstances, early-maturing improved sorghum varieties that are planted in July and mature within 3-4 months have been developed. Moreover, a sustainable cropping system involving legume-early maturing sorghum double cropping has been developed as an alternative to the traditional long-cycle sorghum production to help mitigate crop failure. The legume fits into the short rainy months. However, access to seeds of both component crops could be a challenge. The objective of this study therefore was to establish and assess the feasibility of a farmer-based seed multiplication (FBSM) scheme in enhancing the supply of quality seeds of legumes and sorghum and contributing to climate adaptation. Two activities were implemented in 2015 and 2016 in Mieso district, West Hararghe, Ethiopia. The first activity involved multiplying seeds of two early-maturing and drought-tolerant improved sorghum varieties (Dekeba and Melkam) using a FBSM scheme. The second activity was integrating this scheme into a legume-early maturing sorghum double cropping system. The results of the study show that the FBSM scheme provides much-needed support to smallholder sorghum farmers by offering resources for multiplying and marketing improved sorghum seeds, ensuring seed security, and improving access to quality seeds. The scheme aligns well with the legume-early maturing sorghum double cropping system, thereby enhancing access to compatible seeds and promoting a sustainable cropping system in the region. The scheme presents a viable solution to seed access for smallholder farmers in Ethiopia to enhance seed supply, income, and climate resilience, offering valuable insights for policymakers and stakeholders

Levels of potentially toxic and essential elements in Tocantins River sediment: health risks at Brazil’s Savanna-Amazon interface

The field study aims to address identified research gaps by providing valuable information on the concentration, spatial distribution, pollution levels, and source apportionment of toxic and essential elements in sediment samples from four sampling sites (P1: Beira Rio (urban area), P2: Bananal (rural area), P3: Embiral (rural area), P4: Cidelândia (rural area) distributed along the middle Tocantins River, Brazil. Samples were collected in 2023 from river sections and analyzed using various contamination índices (geoaccumulation index, contamination factor, enrichment factor, pollution load index, sediment pollution index, potential ecological risk coefficients, and integrated risk index). Results indicated that the levels of aluminum, iron, manganese, and selenium exceeded legal standards in that year. Chromium, nickel, copper, zinc, and lead exceeded guidelines, mainly in section P1 for aluminum and section P3 for nickel and lead. Rainy months showed increased presence, indicating seasonal variability. The geoaccumulation index indicated low pollution levels, with lead and nickel notably present near urban and industrial areas. The enrichment factor highlighted elevated concentrations of lead and zinc in industrial areas. Both PLI and SPI indices raise concerns regarding Pb (P4) and Zn (P3) concentrations at specific times of the year. Overall, potential ecological risks were deemed low for most sites. Continuous monitoring and interventions are crucial to preserve water and environmental quality in the region.

Prevalence of Gastro-Intestinal Parasites in Clarias gariepinus Caught in the Gwagwalada River, Gwagwalada, Abuja, Nigeria

This paper reports the prevalence of gastro-intestinal parasites in Clarias gariepinus caught in the Gwagwalada River, Abuja, north central Nigeria. Sixty specimens of wild catfish, C. gariepinus were obtained fresh from fishermen who caught then from the Gwagwalada River during the rainy season months of June to July. They were dissected, the stomach and intestines contentseviscerated and prepared following standard parasitological procedures on glass slides and thereafter, viewed under x400 magnification for the presence of gastro-intestinal parasites. The parasites were identified using the pictorial atlas of parasitic infections and diseases of African fish (1980). On the whole, 27 out of the 60 fish examined were infected with parasites, thus giving a prevalence rate of 45.00%. The protozoa Toxoplasma gondii recorded the highest prevalence rate (34.77%), followed by the cestode, Bothriocephalus gowkongenesis (18.87%). The highest prevalence rate and parasite intensity were also recorded in the 21 – 25 cm length group (20.00% and 13.17 respectively). The 501 – 951 g weight group had the highest prevalence rate (53.64%) and parasite intensity (13.50) and was followed by the 50 -500 g group that recorded 28.48% prevalence rate and 9.56 parasite intensity. The females recorded higher parasite prevalence rate (59.26%) but lower parasite intensity (10.88) than the males. It was concluded that wild C. gariepinus from the Gwagwalada River are moderately infected with gastro-intestinal parasites and that the young and growing fishes harbored more parasites than the older ones.

Evaluating water security in sub‐Saharan Africa: Examining a case study of water supply inventory, accessibility, and predictability on Iwo, Nigeria

AbstractThe security of nations concerning water accessibility by 2030 is under threat due to climate change, potentially hindering global targets outlined in SDG 6. This study assesses the water security of the sub‐Saharan region, focusing on Iwo, Nigeria. Surveys on household water sources, availability, and use were conducted across 12 months among 937 households. Climatic data spanning 31 years (1992–2022) from the Nigeria Meteorological Agency were analyzed for water supply evaluation. Descriptive and inferential statistical analyses were applied to the datasets. Results revealed a predominant 95% involvement of female heads and individuals above 18 years old. Notably, 92.7% spent less than 10 min obtaining water, with 90.5% not paying water tariffs, indicating a predominantly domestic water use pattern, reflecting the agrarian nature of the study area. Analysis of climatic data highlighted water loss during dry season months and previously rainy months (March, April, and August), confirming climate change manifestations. Household water use consistently exceeded supply, ranging from 348.9 to 444.6 L/month, with a per capita value of 148.6 L (4.95 L/day) falling below the WHO recommendation of 10 to 20 L/day. Regression analysis identified three significant predictive models at p < .005, with Model 3 showing a notable predictability (R value of 42.3 at p < .005 and SE of ±79.05941), and it encompasses more of the variables analyzed. The generally low R value suggests the consideration of additional variables for model validity. Urgent and intentional efforts are required to exploit abundant surface water resources for enhanced justice in water accessibility in aligning with the SDG 6 target.

Effects of a landslide on the geochemistry of dissolved major and trace elements in a granite-gneiss forest catchment of Southeast Brazil

This study investigated the hydrogeochemical variations in a scenario following a landslide event in the Soberbo pristine rainforest small catchment (13 km2). The selected catchment is underlain by granite gneiss and located at the Serra dos Órgãos a mountainous region in the Rio de Janeiro, Brazil, that faces frequent high-intensity rainfall events. Stream water sampling, water discharge, and pH and electrical conductivity measurements were conducted monthly from May 2018 to October 2019. In January 2019, a landslide occurred upstream. Concentrations of dissolved organic carbon (DOC), HCO3−, major elements (Ca, K, Mg, Na, and Si), and trace elements (Al, Ba, Ce, Fe, Mn, Nd, Sr, Rb, La, Pr and Sm) were determined. The Spearman correlation and the multivariate analysis (PCA) indicated that during baseflow, rock weathering hydrolysis reactions are the main source of Si, Na, Mg, Ba and Sr. On the other hand, the forest plays a significant role during the rainy months by remobilizing colloidal litter material (represented by the DOC concentration) closely associated with colloidal Al. The landslide promoted a change in local redox conditions, resulting in the early release of Mn-scavenged elements, and about a month later, Fe and LREE, following a deepening in reduced conditions. The Ce/La molar ratio appeared to be a reliable hydrogeochemical redox proxy. The landslide effects persisted for at least nine months. In this case, the traceability of natural geochemical impacts of landslides was achieved through the river hydrogeochemistry in a mountainous small catchment model area.

Rainfall and Extreme Drought Detection: An Analysis for a Potential Agricultural Region in the Southern Brazilian Amazon

In recent decades, the main commercial crops of Mato Grosso, such as soybeans, corn, and cotton, have been undergoing transformations regarding the adoption of new technologies to increase production. However, regardless of the technological level, the climate of the region, including the rainfall regime, can influence the success of crops and facilitate, or not, the maximum production efficiency. This study aimed to define the behavior of the variability in monthly and annual rainfall and its probability of monthly occurrence and calculate the drought index for the northwestern region of Mato Grosso, in the southern region of the Brazilian Amazon. To carry out the study, daily rainfall records were collected, calculating the totals for each month of the historical series for each of the four National Water and Sanitation Agency (ANA) rain gauge stations, Aripuanã (1985–2020), Colniza (2001–2020), Cotriguaçu (2004–2020), and Juína (1985–2020), representing the northwestern region. The annual distribution of rainfall during the periods studied ranged from 1376.2 to 3017.3 mm. The monthly distribution indicated a typical water shortage in the months of June, July, and August. The probability of rainfall near the average for each month was more than 50%. The monthly SPI-1 index revealed a total of 56 months affected by very dry events and 34 extreme dry events. The annual SPI-12 index pointed to seven very dry years and five extremely dry years. Therefore, the region presented high rainfall rates in most years; however, a significant process of drought was also observed, including in rainy months, which are the periods with the greatest demand for the main agricultural crops.

Vegetation and Soil Dynamics : Insights from Prosopis juliflora- Intruded Areas in Hastinapur Wildlife Sanctuary

Ecological study on plant diversity and soil characteristics of two contrasting sites (Prosopis juliflora-invaded and non-invaded) in Hastinapur Wildlife Sanctuary was undertaken to understand the structure of vegetation and soils and implication of exotic dominance in a dry tropical region of India. Seasonal floristic composition was recorded for one year through monthly visits. Phytosociological study of the two sites in each of three seasons was carried out by sampling a total of 120 quadrats (each 1mx1m, n= 20×3×2). Plant species density and abundance was estimated for both sites in each season. Seasonal surface soil (0–10 cm) samples were analyzed for soil pH, moisture content, organic C, and total N. Species occurrences and their relative abundance data were used to estimate alpha and beta diversity. A total of 76 plant species from 29 families were recorded (Malvaceae, Fabaceae and Asteraceae being top dominants). Maximum flora was recorded in rainy season at both sites, higher at non-invaded sites in all seasons. Beta diversity followed similar trend, higher in rainy season and at non-invaded than invaded sites, highest being 13.2 at non-invaded site in rainy season. Dominants changed with site and season. Vegetation patches were distinct in drier seasons compared to rainy months. Soil organic carbon, total nitrogen and C : N ratios were high at invaded sites compared to non-invaded sites except in summer season. While higher diversity and higher similarity amongst different sites in rainy season indicated a homogenization impact in Indian dry tropical regions, higher diversity at non-invaded site suggested implication of diversity-reducing impact of tree invader Prosopis juliflora.

Calculating the Environmental Drought Index using the De Martonne Equation for the Rainy Months in Iraq

Calculating the Environmental Drought Index using the De Martonne Equation for the Rainy Months in Iraq

Quantifying the Impacts of an Urban Area on Clouds and Precipitation Patterns: A Modeling Perspective

AbstractOver the past century, rapid urbanization has greatly altered landscapes and affected atmospheric conditions causing impacts across a wide range of sectors including human welfare, infrastructure, and ecosystems. As a result, there is a growing imperative to improve understanding of urbanization impacts on local and regional weather events and hydroclimates. This study investigates how urbanization affects precipitation and cloud fraction (CF) in the vicinity of Indianapolis. We employ multi‐month simulations using the Weather Research and Forecasting model to: (a) assess the impact of an urban area on precipitation and CF, (b) quantify how this impact varies with urban growth, and (c) examine the main mechanisms through which the city alters the local hydroclimate. Specifically, two perturbed simulations, where the urban land cover is either replaced by croplands or is increased in size, are also performed for the two rainiest months. Comparisons of the control run with no city against the perturbed runs indicate statistically significant impacts of the urban area in enhancing precipitation amounts, frequency and low‐level CF, particularly within the first 100 km radius downwind of the city boarder. The urban environment is found to increase precipitation efficiency over the city and in downwind regions. Temperature at 2 m height, planetary boundary layer height, turbulent kinetic energy, and convective available potential energy, are also enhanced in the perturbed runs and drive changes in vertical mixing, downwind precipitation amounts, frequency and low‐level height CF. All these changes appear to be a non‐linear function of the city size.

Air quality and attributable mortality among city dwellers in Kampala, Uganda: results from 4 years of continuous PM2.5 concentration monitoring using BAM 1022 reference instrument.

Air pollution is a known risk factor for non-communicable diseases that causes substantial premature death globally. Rapid urban growth, burning of biomass and solid waste, unpaved sections of the road network, rising numbers of vehicles, some with highly polluting engines, contribute to the poor air quality in Kampala. To provide evidence-based estimates of air pollution attributable mortality in Kampala city, with focus on ambient fine particulate matter (PM2.5). We utilized a time series design and prospectively collected data on daily ambient PM2.5 concentration levels in micrograms per cubic meter (μg/m3) using a Beta Attenuation Monitor (BAM-1022) in Kampala city, Uganda. We combined the PM2.5 data with all-cause mortality data obtained from the Uganda Bureau of Statistics and the Ministry of Health in Kampala. We calculated attributable risk estimates for mortality using the WHO AirQ+ tools. Overall, the annual average concentration for PM2.5 for the period of 4 years, 2018-2021, was 39 μg/m3. There was seasonal variation, with the rainy season months (March-June and October-December) having lower values. PM2.5 concentrations tend to be highest in the morning (09.00 h) and in the evening (21.00 h.) likely due to increased vehicular emissions as well as the influence of weather patterns (atmospheric temperature, relative humidity and wind). Saturday has the most pollution (daily average over 4 years of 41.2 μg/m3). Regarding attributable risk, we found that of all the deaths in Kampala, 2777 (19.3%), 2136 (17.9%), 1281 (17.9%) and 1063 (19.8%) were attributable to long-term exposure to air pollution (i.e., exposure to PM2.5 concentrations above the WHO annual guideline of 5 μg/m3) from 2018 to 2021, respectively. For the 4 years and considering the WHO annual guideline as the reference, there were 7257 air pollution-related deaths in Kampala city. Our study is the first to estimate air pollution attributable deaths in Kampala city considering the target as the WHO annual guideline value for PM2.5 of 5 μg/m3. Our monitoring data show that fine particulate matter air pollution in Kampala is above the WHO Air Quality Guideline value, likely resulting in substantial adverse health effects and premature death. While further monitoring is necessary, there is a clear need for control measures to improve air quality in Kampala city.

Seasonal dynamics of sand flies in Lençóis Maranhenses National Park: a tourist destination and endemic area for leishmaniasis.

Numerous sand fly species have been reported in Lençóis Maranhenses National Park (LMNP) in Northeast Brazil, including important Leishmania vectors, making the park an endemic area for tegumentary and visceral leishmaniasis. We evaluated sand fly abundance monthly over 7 years, correlating it with environmental variables and monthly tourist numbers in LMNP. Sand fly species were observed throughout the year, with Lutzomyia longipalpis Lutz & Neiva and Nyssomyia whitmani Antunes and Coutinho (Diptera: Psychodidae) being the most abundant species, especially from April to June. In addition to seasonal abundance patterns, Lu. longipalpis showed increasing abundance throughout 2013 until April 2014, whereas Ny. whitmani exhibited a consistent increase throughout the study period. Redundancy analysis indicated that monthly sand fly abundances increased with humidity but decreased with mean temperature and wind speed. Ecotourists mainly visit the park from May to September when interdune lagoons are full, coinciding with high-frequency vector activity during the rainy months (May-June). Tourists also visit in January and February during school holidays, when the rains begin and sand fly abundance increases, and in July, when sand fly abundance decreases. To date, no instances of infected tourists have been recorded, likely because visits to LMNP occur during the day when sand flies are inactive. However, there is a potential risk of vector exposure if tourists engage in nighttime cultural visits to villages around the park, where leishmaniasis cases occur annually.