This study focused on the content of fine particle air pollution in the city of Douala. Several studies have analyzed pollution problems due to road traffic in Douala, Cameroon. Particle concentration levels are higher in heavy traffic than in light traffic. The populations exposure to air pollution in cities is higher near roads. Several studies have analyzed pollution problems due to road traffic in Douala, Cameroon. In this city, the traffic density at the intersections is indeed higher. Thus, the question is as follows: Are these traffic areas hotspots of increased PM exposure levels? To determine it, four particle size fractions (PM₁₀, PM_2.5, PM₅, and PM₁) were collected using an OC300 Gas and Dust Particle Laser Detector for three months at different traffic locations (roundabouts or/and crossroads). Statistical analysis of the data shows very high concentrations at most measurement sites. PM concentrations at the different measurement sites are around 35.69-68.08 µg m⁻³ for PM1, 50.72-99.13 µg m⁻³ for PM_2.5, 54.11-111.22 µg m⁻³ for PM₅, and 57.97-119.25 µg m⁻³ for PM₁₀. Exceedances of WHO daily guidelines for PM_2.5 (45 µg m⁻³) and PM₁₀ (15 µg m⁻³) were found during the measurement campaign, indicating that crossroads are the pollution hotspots in urban areas. Occupation of the roadsides for various economic activities (painting, restaurants, donut shops, etc.) is common in Cameroon, increasing health risks for people working around the roadside. Thus, crossroad locations are areas where the level of exposure to PM_x is the highest on road traffics.

Les déchets biomédicaux (DBM) constituent un problème sanitaire et environnemental. Aussi, une étude a été menée pour élaborer un système de gestion des déchets biomédicaux dont la mise en oeuvre permettra d’améliorer la santé publique, tout en respectant les préoccupations environnementales, techniques et socioculturelles. Il s’agit d’une étude transversale descriptive qui s’est déroulée du 16 au 31 Janvier 2018. Un questionnaire soumis aux responsables des formations sanitaires (FOSA), chefs de services, surveillants de services et responsables de l’hygiène hospitalière et un entretien avec les personnels de soins et les opérateurs d’incinérateurs ont permis d’apprécier les mécanismes et les connaissances sur la gestion des DBM. Sur les 150 questionnaires distribués, 98 réponses ont été obtenues, soit un taux de réponse de 65,3 %. Un entretien avec 75 travailleurs directement impliqués dans la gestion des DBM et des observations sur la gestion des DBM au niveau des 86 services ont été réalisés. Les déchets tranchants et piquants et ceux de sang et de fluides étaient trouvés dans tous les services, à l’exception des pharmacies, les déchets pharmaceutiques dans 66 services, les déchets infectieux dans 49 services et les déchets anatomiques dans 11 services. Le tri des DBM était inadapté dans 83,5 % des FOSA et l’utilisation du système de codage par couleur inexistant dans les FOSA PBF et non PBF. Des boîtes de sécurité pour le recueil des objets tranchants et piquants étaient disponibles dans 62,5 % des FOSA PBF et leur utilisation effective dans 31,1 % d’entre eux. Ceux Dans la majorité des FOSA non PBF, un conditionnement inadapté était noté sous la forme d’une utilisation de bouteilles et poubelles en plastique po r le recueil et d’un remplissage des boîtes de sécurité avec des débordements. L’élimination des DBM était effectuée dans de vieux incinérateurs ou des fours artisanaux, avec d’importantes émanations de fumées dans 80% des FOSA. Les conditions de travail étaient jugées mauvaises par 81,3 % des travailleurs interrogés et les équipements de protection individuelle disponibles dans seulement 25,3 %des FOSA non PBF et à 65% dans les PBF. Les connaissances sur la gestion des DBM étaient jugées insuffisantes par 92,6 % des personnes interrogées et les risques sanitaires liés aux DBM connus par 90 %. Toutefois les impacts sur le plan sanitaire et environnemental a été plus relevé dans les FOSA non PBF à 70 % que chez les FOSA PBF à 30 %. A exception de l’Hôpital Régional de Bertoua qui faisant partie des FOSA PBF a présenté des impacts majeurs sur la santé et l’environnement. Mots clés Déchets biomédicaux, Gestion, Pollution, Risques, Environnement·

The management of wastewater in developing countries is a crucial challenge. The overall objective of this study was to evaluate the impact of discharges from the slaughterhouse Etoudi on physico-chemical and bacteriological water quality of the Ako'o. This study was conducted in two phases. The first phase (preliminary) in April 2022, during which a prospecting along the rivers and its watershed was performed. The second phase extended from May to October 2022, was dedicated in the collection of hydrological data, samples of water samples and bacteriological at each station coupled to the data analysis. This wastewater were collected from different stations, stored in refrigerated cooler and brought back to the laboratory for monitoring physical, chemical and bacteriological parameters according to standard protocols. The results show the effluent discharges from the slaughterhouse Etoudi exhibit high levels of pollution physicochemical (CND, MES, NO₃, NH₄⁺, PO₄^3ˉ, COD and BOD 5) and bacteriological (CF and SF) in the receiving environment having a negative impact on the watercourse Ako'o. negative impacts were increased to 90% by the dunghill faeces oxen or invading the rights of way areas. Existing gutters are littered with faeces of any kind and are not priests. Which causes recurring floods during the rainy season, the proliferation of insects and rodents and the emanation of foul odors and the persistence of certain diseases such as malaria typhoid fever, dysentery etc. this wastewater join the River Ako'o. This constitutes a major source of environmental pollution in general and rivers of waters Ako'o in particular. The positive impacts threshold is the use of cattle feces for farming populations who find themselves in different fields. Effluent discharges from the slaughterhouse Etoudi present an environmental and health risk because of high concentrations of physicochemical and bacteriological pollutants. A treatment system is needed to ensure environmental and health safety.

This study assesses the extent to which cumulative impacts are considered when evaluating the environmental and social impacts of development projects in proximity to a protected area. The applicability of the Sorensen and Rau method for evaluating these impacts was also investigated. The methodological basis of this study is the content analysis of eight environmental and social impact assessment reports. These reports were assessed using an assessment grid divided into six blocks of questions. This grid was developed on the basis of good practice and implemented through exchanges with key stakeholders. It was also implemented in accordance with the four stages recommended by Sorensen and Rau. The results demonstrate that Block 1, which pertains to the role of the Campo-Ma'an National Park in the study, has a level of consideration of 79%. Block 2, which pertains to the analysis of the impact of the projects on the Park, was considered to a degree of 81%. Block 3, which addresses the consideration of cumulative impacts on the Park, was addressed to a limited extent, at 52%. Block 4, which pertains to public participation, has a compliance rate of 47%. Block 5, which pertains to the integration of the Environmental and Social Management Plan, was considered to the extent of 67%. Block 6 addressed 47% of the cumulative impacts on the park in the Environmental and Social Management Plan. The findings of the Sorensen and Rau method indicate that the component associated with great ape populations remains of significant value, with a criticality score of 19.52. Those components associated with the park's surface area, ecological corridors and habitat remain at an average criticality value of 11.4, 11.1 and 10.22, respectively. This suggests that the park's valued components could suffer from the cumulative effects of the various projects, particularly those associated with great apes. The study revealed that projects do not systematically integrate cumulative impacts due to a dearth of data, and that this shortcoming could be addressed through a combined matrix and network approach. It would be more prudent to consider the digitization of systems in relation to impact analysis at a time when digital technology is optimizing systems.