Global warming may influence blackfly ecology by changing the environmental conditions that affect aquatic development and adult activity. This study assessed local bioecological conditions associated with blackfly abundance and daily biting activity in the Touba Department, northern Côte d’Ivoire. During three consecutive days in December 2023, adult female blackflies were collected using human bait and haemolysis tubes at two locations: the Bagbê River bridge and an agricultural field 10 km from the river. Microclimatic conditions and selected physicochemical properties of river water were recorded. Of 801 blackflies collected, 582 were captured at the field site and 219 at the bridge site. Morphological identification assigned 794 specimens to the savannah group and seven to the forest group of the Simulium damnosum complex. Hourly biting activity increased after noon at both sites and peaked between 3 and 4 p.m. The highest recorded hourly biting rate was 120 bites per person at the field site. Mean air temperatures were similar at the field and bridge sites, with no statistically significant difference (p = 0.917). The reported analyses indicated negative associations of turbidity and conductivity with blackfly density density (p = ˂ 0.01; R2 = - 0.859), whereas water temperature showed a positive association (p = 0.02; R2 = 0.684). These observations indicate substantial human exposure to blackfly bites during the sampling period. Continued entomological and environmental surveillance is warranted, although the findings do not establish a long-term effect of global warming or confirm ongoing parasite transmission.
In Cameroon, forest resource management is carried out in production forests, particularly within Forest Management Units (FMUs). However, the impact of logging on stand structure and carbon stocks before and after logging remains poorly documented. The objective of this study is to assess the influence of logging activities on stand structure and carbon stock in logged and unlogged forest stands within UFAs 10 038 and 10 054. Six permanent plots measuring 200 x 200 m were established in logged and unlogged stands. Three plots were therefore established in the logged stands and three in the unlogged stands. Within each permanent plot 20 m x 20 m quadrats were established at the four sides of the plot’s base to inventory all woody species with a DBH ≥ 10 cm. The results showed that species richness is higher in the unlogged stands (152 species) than in the logged (141 species). Two of the stands studied exhibited an inverted “J”-shaped structure. There is no significant difference between logged and unlogged in terms of density and basal area. The carbon stored in unlogged stands (55.61 tC/ha with a mean of of 18.53 tC/ha) is not significantly different from that in logged (52.32 tC/ha with a mean of of 17.44 tC/ha). These study indicate that well-planned forest harvesting, implemented in accordance with the principles of sustainable forest management, can enable timber production without significantly degrading stand structure or reducing carbon stocks.
Rice (Oryza sativa L.) is a major staple food crop worldwide, particularly in Asia, where its cultivation plays an important role in food security and agricultural livelihoods. However, conventional continuous flooding requires considerable irrigation water and promotes methane emissions from paddy soils. Alternate Wetting and Drying (AWD) is a water-saving irrigation technique that reduces unnecessary water application by allowing the field to dry periodically before re-irrigation. Although AWD can improve water-use efficiency and reduce greenhouse gas emissions, its manual implementation requires regular field monitoring and timely irrigation. Automated Alternate Wetting and Drying (AAWD) offers a promising solution by integrating sensors, microcontrollers, Internet of Things (IoT) technology and automated pumping systems to regulate irrigation according to predetermined water-level thresholds. This review examines the principles of paddy water management, irrigation requirements, AWD practices, sensor-based monitoring technologies and automation strategies for sustainable rice cultivation. It also discusses the effects of AWD and AAWD on irrigation water use, crop productivity, water-use efficiency and greenhouse gas emissions, particularly methane (CH₄) and nitrous oxide (N₂O). Previous studies have demonstrated that AWD can substantially reduce irrigation water consumption and methane emissions while generally maintaining rice yield under appropriate management conditions. However, excessive soil drying, variations in soil properties, increased nitrous oxide emissions, equipment costs and unreliable water supplies may limit its effectiveness. Sensor-based automation can improve irrigation precision, reduce labour requirements and support consistent implementation of AWD. The review highlights the potential of AAWD to promote efficient water management, maintain crop productivity and reduce the environmental impacts of paddy cultivation. Further research is required to improve system affordability, field-level reliability and adaptability under different agroclimatic conditions.
Heavy-metal contamination of wastewater has increased interest in using agricultural waste as potential low-cost bioadsorbents. This study compared rice husk (RH), sugarcane bagasse (SB), and pinecone (PC) for the removal of Pb(II) and Cu(II) from wastewater and characterised the materials using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). The untreated residues were washed, ground, and sieved to 200–250 µm, then investigated in triplicate batch experiments at an adsorbent dose of 10 g/L, an agitation speed of 150 rpm, a contact time of 120 min, and a temperature of 27 ± 2 °C. SEM revealed porous, layered, and fibrous structures in RH; granular and fibrous structures in SB; and rough, flaky surfaces with microcracks and pores in PC. EDX showed that SB had the highest carbon content (68.4 ± 3.4 wt.%), followed by PC (67.6 ± 3.3 wt.%) and RH (48.0 ± 2.4 wt.%). RH had the highest silicon content (19.8 ± 0.9 wt.%). PC recorded the highest Pb(II) removal efficiency (72.94 ± 2.60%), followed by RH (51.20 ± 2.20%) and SB (27.91 ± 1.40%). Cu(II) removal was also highest for PC (98.11 ± 3.20%), followed by SB (94.36 ± 2.70%) and RH (88.40 ± 2.40%). Under the studied conditions, PC performed best for both metals and merits further assessment for wastewater treatment. Further studies under a wider range of operating conditions are needed to establish the suitability of pinecone as a practical bioadsorbent for wastewater treatment.
Contamination of edible vegetables by heavy metals is a potential pathway of dietary exposure and requires assessment using crop-specific measurements and age-related consumption assumptions. A field investigation was conducted during 2023–24 and 2024–25 at Bachaoli Bujurg (Site 1) to assess heavy metal accumulation in commonly consumed vegetables and evaluate the potential health risks associated with dietary exposure to contaminated vegetables. Five vegetables, namely spinach, brinjal, cabbage, okra and tomato, were evaluated for the concentrations of lead (Pb), cadmium (Cd), zinc (Zn), iron (Fe) and copper (Cu), along with exposure parameters, estimated daily intake (EDI), target hazard quotient (THQ) and hazard index (HI). Among the vegetables studied, spinach recorded the highest pooled Pb concentration (0.407 mg kg⁻¹), followed by brinjal (0.355 mg kg⁻¹), cabbage (0.328 mg kg⁻¹), okra (0.3125 mg kg⁻¹) and tomato (0.284 mg kg⁻¹). Cadmium concentration was also highest in spinach (0.082 mg kg⁻¹) and lowest in tomato (0.0415 mg kg⁻¹). In contrast, okra recorded the highest pooled concentrations of Zn (0.1315 mg kg⁻¹) and Fe (0.1305 mg kg⁻¹), whereas tomato showed comparatively lower concentrations. Copper concentration was comparatively higher in okra, which was also reflected in its higher estimated dietary intake. The exposure parameters indicated a higher vegetable ingestion rate in adults, increasing from 0.21 kg day⁻¹ in 2023–24 to 0.30 kg day⁻¹ in 2024–25, with a pooled mean of 0.255 kg day⁻¹, whereas children showed a pooled ingestion rate of 0.105 kg day⁻¹. The exposure frequency was 365 days year⁻¹ for both age groups. Adults had pooled exposure duration of 30.15 years, compared with 7.07 years for children, while the pooled average body weights were 57.84 and 15.615 kg, respectively. The estimated daily intake of Pb was highest through spinach consumption (0.0013 mg kg⁻¹ day⁻¹), followed by brinjal (0.0012 mg kg⁻¹ day⁻¹), whereas tomato showed the lowest pooled Pb intake (0.0008 mg kg⁻¹ day⁻¹). For Cd, spinach recorded the highest pooled EDI (0.0002 mg kg⁻¹ day⁻¹), while Zn intake was highest through spinach and okra (0.0004 mg kg⁻¹ day⁻¹). Copper showed the highest pooled EDI in okra (0.0008 mg kg⁻¹ day⁻¹). The pooled THQ values for Pb, Cd, Zn, Fe and Cu were 0.00133, 0.002455, 0.001025, 0.000625 and 0.00112, respectively. All THQ values were substantially below the benchmark value of 1.0, indicating low estimated non-carcinogenic risk from individual metals through vegetable consumption. The pooled hazard index (HI) was also considerably below 1.0, indicating that the combined exposure to Pb, Cd, Zn, Fe and Cu through consumption of the studied vegetables was below the commonly used non-carcinogenic risk threshold. Overall, spinach exhibited comparatively greater accumulation of Pb and Cd, whereas okra showed higher accumulation and dietary intake of Zn, Fe and Cu. The findings emphasise the importance of continuous monitoring of heavy metal concentrations in agricultural soils and vegetables and the assessment of age-specific dietary exposure to ensure long-term food safety under the agro-climatic conditions of the Bachaoli Bujurg region.
