The successful implementation of the Clean Air Act along with the associated air management procedures in Lebanon is conditioned by the implementation of a comprehensive air quality monitoring and reporting program on a national level. This requires a number of pre-requisites such as the development of clear objectives for conducting air quality monitoring, determining criteria air pollutants of interest to be monitored, planning and selecting the appropriate type of air quality monitoring network, identifying the kind of technical staffing and training required for maintenance and data management, determining the availability or lack of resources, and the budget constraints and optimizing public transparency by disseminating documented monitoring data.
Starting with the identification of the monitoring network, the method of choice for determining hotspots in Lebanon was based on the inventory of the different emission sources in Lebanon coupled to the model developed by l’Agence de l’Environnement et de la Maîtrise de l’Énergie (ADEME). Seven monitoring classes were defined based on meteorological, topographical, source distribution and source emission. They are urban, suburban, rural, regional, national, industrial, and traffic. The model is based on Global Information System (GIS) analysis of the geographical characteristics for primary pollutants such as NO2, and for secondary pollutants, a physico-chemical model; “CHIMERE”[1], is adopted in order to account for all precursors leading to its formation, decomposition and dispersion over several kilometers into the atmosphere. When applied to Lebanon, 29 hotspots were identified based on population agglomeration, emission sources, and industrial sites. They are distributed among background urban station, near-city background station, urban traffic station, industrial station, quarries, national station, and regional rural station.
While this is an ideal case scenario, the application of such monitoring system will incur a huge financial burden on the government. It is recommended that the proposed plan is implemented in phases starting with the first five background urban stations for centers of principal agglomerations. These sites exhibit high population density and do represent sites most indicative of the population exposure of more than 60% of the Lebanese population. Background urban sites are characterized by emission sources such as vehicle fleet, dust resuspension and small scale industry, hence, NOx, PM10, and PM2.5 are suggested as the most relevant pollutants to be monitored in real time. A cost assessment of monitoring equipment, installation, communication, training and operation for different case scenarios was presented and both fixed and moving monitoring stations were evaluated.
As sharing of the air quality information is crucial, both for awareness raising and as a driver for change, it is suggested that the collected information be displayed to the public through a website including a map showing the location of stations and the level of air pollution in comparison to the Lebanese Air Quality Index (LAQI) based on color codes (Green: good, yellow: moderate, Orange: unsafe for sensitive groups, Red: unhealthy, Violet: very unhealthy, Brown: hazardous levels) formulated based on the review of the types of monitoring and reporting strategies pursued by the different countries.
[1]The CHIMERE model uses meteorological model fields and emissions fluxes and calculates deterministically their behavior in the troposphere. The results are three-dimensionalfields of chemical concentrations.