The identification of heavy metals in the atmosphere has increased a strong and growing interest. Thereby, monitoring of elements in aerobiological samples could be a powerful tool for detection of environmental pollution. In this work, a simple and fast method for the determination of trace metals bound to aeroparticles such as pollen was optimized. A single-step procedure for the dissolution of aerobiological samples in nitric acid and further determination by inductively coupled plasma mass spectrometry (ICP-MS) with a high-efficiency sample introduction system was developed. The procedure involved low dilution and low detection limits with adequate precision and its direct introduction into the ICP-MS system. The novel method proposed was successfully applied to determine five elements in concentrations from 0.04 mg g⁻¹ (U) to 14.1 mg g⁻¹ (Mn) in aerobiological samples. Through this procedure, the most significant correlations between pollen of Cupressaceae, Ulmus, and Moraceae with Mn, and pollen of Moraceae with Pb were found. This methodology could be a very useful tool to assess air pollution. We are not only proposing a new strategy to analyze air samples particles but also giving new information of the elemental composition carried by pollen. Graphical Abstract Development of elements determination in aerobiological samples based on the nitric acid dissolution and its direct introduction into the ICP-MS system

Atopic asthma is characterized by the presence of sensitization to common aeroallergens, which tends to have a worse prognosis than non-atopic asthma. The objectives were to determine the prevalence of aeroallergens sensitization in the Lebanese pediatric asthmatic population and determine the relationship between allergens sensitization (indoor and outdoor) and age, area of residence and altitude. A sample, consisting of 919 asthmatic children (aged 1 to 18 years, from 2010 until 2017), underwent skin prick testing (SPT) with 21 common allergens: 5 grasses (cocksfoot, sweet vernal-grass, rye-grass, meadow grass, timothy), Parietaria, olive, Dermatophagoides pteronyssinus and Dermatophagoides farina (DP-DF), dog and cat dander, Alternaria longipens, Aspergillus fumigatus and nidulans, Cupressaceae, pine, German cockroach, and 4 cereals (oat, wheat, barley, maize). Seven hundred fifty-two patients had positive SPT. The distribution of sensitization was as follows: DP-DF 59%; 5 grasses 34%; 4 cereals 33.9%; cat 29.9%; Alternaria 27.9%; Parietaria 23%; dog 21.9%; olive 20.5%; Aspergillus mix 18.6%; Cupressaceae 18.2%; pine 17%; cockroach 15.3%. House dust mites sensitization was frequent at lower altitude (< 900 m) (56.3%) and in the whole country (a median prevalence of 53.05%) except for the Beqaa region (negative HDM in 82.4%). Non-atopic asthma was more frequent in early childhood (40.5% at 1–4 years vs 11.2% at 11–18 years). The sensitization rate increased with age, starting at 5 years. Higher age (aOR = 1.24) and altitude less than 900 m compared with ≥ 900 m (aOR = 2.03) were significantly associated with the presence of aeroallergens in children. House dust mites and grasses are the most common allergens in Lebanese asthmatic children. Non-atopic asthma is more frequent at early age. Lebanese children with asthma showed a polysensitized pattern starting at 5 years.

A greenhouse experiment was carried out in order to investigate the effects of arbuscular mycorrhizal (AM) fungi inoculation and the use of composted olive waste (COW) in the establishment of Tetraclinis articulata and soil properties in a heavy metal-polluted soil. The treatments assayed were as follows: AM + 0 % COW, AM + 1 % COW, and AM + 3 % COW. The higher doses of COW in combination with AM fungi increased shoot and root biomass production of T. articulata by 96 and 60 %, respectively. These treatments trended to improve the soil properties evaluated, highlighting the C compounds and N as well as the microbiological activities. In relation to the metal translocation in T. articulata, doses of COW applied decreased the Cr, Ni, and Pb contents in shoot, as well as Cr and As in root, although the most of them reached low levels and far from phytotoxic. The COW amendment aided Glomus mosseae-inoculated T. articulata plants to thrive in contaminated soil, mainly through an improvement in both nutrients uptake, mainly P and soil microbial function. In addition, the combined use of AM fungi plus COW could be a feasible strategy to be incorporated in phytoremediation programs because it promotes soil properties, a better performance of plants for supporting the stress in heavy metal-contaminated soils derived from the mining process, and also can be a good way for olive-mill waste disposal.