In the present study, the daily dose in terms of particle surface area received by citizens living in different low- and middle-income countries, characterized by different lifestyles, habits, and climates, was evaluated. The level of exposure to submicron particles and the dose received by the populations of Accra (Ghana), Cairo (Egypt), Florianopolis (Brazil), and Nur-Sultan (Kazakhstan) were analyzed. A direct exposure assessment approach was adopted to measure the submicron particle concentration levels of volunteers at a personal scale during their daily activities. Non-smoking adult volunteers performing non-industrial jobs were considered. Exposure data were combined with time-activity pattern data (characteristic of each population) and the inhalation rates to estimate the daily dose in terms of particle surface area.The received dose of the populations under investigation varied from 450 mm² (Florianopolis, Brazil) to 1300 mm² (Cairo, Egypt). This work highlights the different contributions of the microenvironments to the daily dose with respect to high-income western populations. It was evident that the contribution of the Cooking & Eating microenvironment to the total exposure (which was previously proven to be one of the main exposure routes for western populations) was only 8%–14% for low- and middle-income populations. In contrast, significant contributions were estimated for Outdoor day and Transport microenvironments (up to 20% for Cairo, Egypt) and the Sleeping & Resting microenvironment (up to 28% for Accra, Ghana), highlighting the effects of different site-specific lifestyles (e.g. time-activity patterns), habits, socioeconomic conditions, climates, and outdoor air quality.

This study records the extent of microplastics (MPs) in the surface water, sediments, and fishes of the Mediterranean and Red seas in Egypt. In sediment and water samples, the Ras Gharib station in the Red sea and Damietta and Port Said stations in the Mediterranean sea exhibited the highest microplastic abundance, while the lowest concentration was found in the Ain Sukhna station in the Red Sea and Marsa Matruh station in the Mediterranean sea. Rayon and polyethylene terephthalate were the most frequently found polymers in fishes. The results highlighted the abundant existence of microplastics in sediments, water, and fishes of the Mediterranean and Red seas, thereby improving our understanding of the environmental risks posed by microplastics to fisheries and marine ecosystems and the need for measures to diminish the flux of plastics to the marine settings.

Marine algae have made a strong contribution to global food security in the future. This study is the first report describing the concentration, pathways, and interactions of halogens in 15 species of marine algae collected from the Eastern Harbor in Alexandria, Egypt, relative to 22 key variables. The relationship between halogen content and chemical and biochemical parameters was studied through multivariate analysis. Among all the tested algae, the iodine content was the lowest (2.53–3.00 μg/g). The range of fluoride and chloride in macroalgae (1.12–1.70 and 0.10–0.46 mg/g) was smaller than that of microalgae (0.10–0.46 and 1.48–3.17 mg/g). The bromide content in macroalgae (0.36–5.45 mg/g) was higher than that in microalgae (0.40–0.76 mg/g). The halogen content in macroalgae was arranged in the order of Br > F > Cl > I. In addition, the biochemical parameters such as carbohydrates, proteins, lipids, and certain heavy metals (Fe, Zn, Cu, Mn, Pb, Ni, Co, Cd, and Cr) were determined. Calories, energy, total antioxidant activity (TAC), K/Na, and ion quotient amounts were estimated. The results showed that the green seaweed species had the highest TAC content. In most of the studied algal species, the calculated ion quotient referred to their likelihood of overcoming high blood pressure. The estimated daily intake (EDI) of algae showed no adverse effects on human health. Most of the research variables are below the acceptable WHO/FAO level. Generally, the calorie content of the selected algae is less than 2 kcal, which makes the algae considered an alternative source of healthy food to reduce obesity.Graphical abstract

Though having an economic and ecological impact on Marriott Lake management in Egypt, water hyacinth (Eichhornia crassipes) is an aquatic floating macrophyte with a known phytoremediation potential. In order to assess its remediation potential, pilot floating treatment wetlands (FTWs) with E. crassipes were built in duplicates to evaluate the removal of nutrients and heavy metals from the polluted lake water. The experimental design included units with different water depths (15, 25, and 35 cm; D₁₅, D₂₅, and D₃₅, respectively) and plant coverage (90, 70, 50, and 0%; P₉₀, P₇₀, P₅₀, and P₀, respectively). The pilot FTWs were monitored over a 7-day operation cycle to identify the optimum combination of design (plant coverage, water depth) and operation (hydraulic retention time; HRT) parameters needed for maximum BOD₅, TN, NH₄-N, and TP removal. NH₄-N removal reached 97.4% in the D₂₅P₅₀ unit after 3 days, BOD₅ 75% in the D₁₅P₉₀ after 3 days, TN 82% in the D₂₅P₇₀ after 4 days, and TP 84.2% in the D₃₅P₇₀ after 4 days. The open-water evaporation rate was higher than the evapotranspiration rate in the planted units, probably due to the warm climate of the study area. Metals were also sufficiently removed through bioaccumulation in plant tissues in the order of Fe > Pb > Cu > Ni (62.5%, 88.9%, 81.7%, and 80.4% for D₂₅P₅₀, D₂₅P₇₀, D₂₅P₅₀, and D₂₅P₉₀, respectively), while most of the assimilated metal mass was translocated to the plant roots. The biochemical composition of the plant tissue was significantly different between the shoot and root parts. Overall, the FTW with 70% E. crassipes coverage, 25-cm water depth, and an HRT of 3–5 days was identified as the optimum design for effective remediation of the polluted Marriott Lake in Egypt.

This study is the first in forming an integrated up-to-date spatial analysis linking heavy metal contamination among three different compartments of Lake Edku ecosystem to human health effects. The study determined the concentrations of iron (Fe), nickel (Ni), lead (Pb), chromium (Cr), and cadmium (Cd) in sediment and water samples collected from 12 stations covering the entire lake, as well as in the liver and muscle tissues of the three commercially edible fish species (African sharptooth catfish (Clarias gariepinus), Blue tilapia (Oreochromis aureus), and Redbelly tilapia (Tilapia zillii)), during winter 2019. Cartographic maps investigating the spatial contamination pattern of each metal in sediment and water samples along the entire lake, as well as correlation analysis between metal pairs, were generated. Moreover, the study examined the affinity of metal transfer among the three compartments and assessed the probability of being exposed to non-carcinogenic health hazards from the consumption of the abovementioned species. Results revealed that Fe and Cd recorded the highest and lowest mean concentrations, respectively, in sediment, water, and fish samples. The mean concentrations of Cd, Pb, and Ni in the water of Lake Edku, as well as the mean concentrations of Cd, Pb, and Cr in muscle tissues of the three examined fish species, exceeded the permissible limits. The northwestern part of the lake exhibited the highest concentrations of Fe, Ni, and Cr in Lake Edku’s sediment with strong significant positive correlations recorded between Fe–Ni, Fe–Cr, and Ni–Cr pairs suggesting sharing the same contamination source. Concerning Lake Edku’s water, the northwestern area displayed the highest concentrations for all metals. Moreover, Cd, Pb, and Cr exhibited nearly the same spatial contamination pattern with the hotspot located in the western part of the lake. Strong significant positive correlations were found between Cd–Pb, Cd–Cr, and Pb–Cr pairs in surface water, suggesting sharing the same origin of dispersion. The three fish species accumulated heavy metals from water several folds higher than from sediments, indicating that water is the main source of the intensive transfer of heavy metals to the three fish species. Based on the consumption of the three investigated fish species, children recorded the highest estimated daily (EDI) and weekly intakes (EWI) of heavy metals followed by adults. Regardless Pb, EWI values indicated that there are no significant health risks through fish consumption from the examined metals recommending that children should consume less than 85.227 g/day African sharptooth catfish muscle, 108.696 g/day Blue tilapia muscle, and 97.403 g/day Redbelly tilapia muscle to assure their health. Moreover, adults should consume less than 397.727 g/day African sharptooth catfish muscle, 507.24 g/day Blue tilapia muscle, and 454.54 g/day Redbelly tilapia muscle. The estimated hazard quotient (HQ) of all metals was lower than or close to the safe values of one for children and adults in the three investigated fish species indicating the absence of potential non-carcinogenic threats. The hazard index (HI) estimated for the five examined heavy metals in each of the investigated fish species was below one in adults only. Regarding the total hazard index estimated from consuming the three fish species, both children and adults may be subjected to non-carcinogenic risk.

Three species of freshwater planktonic green microalgae: Ankistrodesmus braunii, Ankistrodesmus falcatus, and Scenedesmus incrassatulus, were isolated from the Nile water in Upper Egypt. These microalgae were exposed to nutritional (nitrogen, phosphorus, and iron) limitations and salinity stress to study their effects on the algal growth and to elevate the lipid content within their cells. The results indicated that exposure to these conditions had a significant impact on the algal growth. The lipid content of the studied algae increased as a result of the salinity stress. The highest lipid content was recorded in A. braunii culture treated with 50 mM NaCl (34.4% of dry weight) and S. incrassatulus cultures treated with 100 mM NaCl (37.7% of dry weight) on the 6th day of cultivation, while the culture of A. falcatus treated with 100 mM NaCl recorded the maximum lipid content (53% of dry weight) on the 10th day of the experiment. The biodiesel quality parameters of the fatty acid methyl ester profile of S. incrassatulus appeared to be in agreement with the international criteria. S. incrassatulus could be regarded as a quite promising feedstock for the biodiesel production.

Flax industry has an adverse effect on health status of exposed workers especially in developing countries with lack of appropriate safety measures to identify the health hazards, health disorders among workers in flax and oil company, and to assess the applied safety measures in the factory. A cross sectional study was conducted in Tanta Flax and Oil Company in Egypt. The company includes eight factories which are divided into four departments according to the manufacturing end products. The study was conducted from August 2018 to December 2019 on 353 workers out of 400 workers. An interview questionnaire and clinical medical examination were done to assess the health status of exposed workers. Check list from occupational safety and health administration (OSHA) standards was filled by researcher to check safety measures in work place environment. Respiratory manifestations were detected in 65% of the examined workers in flax manufacturing departments while allergic manifestations were more obvious in formaldehyde factory department. Approximately one quarter of workers complained that personal protective equipment’s are not available. Regarding the mask for dust, nearly half (44.5%) of the workers rarely used them, and only 7.1% always use them. Byssinosis was obvious among workers in flax manufacturing and particle board manufacturing department with statistically significant differences between the four departments, in which 36.9% and 24.1% of workers in these two departments suffered from chest tightness, respectively. The safety measures were inadequate in flax manufacturing departments and to somewhat sufficient in formaldehyde factory department. Most of exposed workers had inadequate health status due to lack of standard safety measures. Therefore, periodic medical examination should be done regularly with investigation of pulmonary functions of exposed workers with application of high level of safety measure standards in the work place environment.

The present study aims to investigate the impact of remittances on CO2 emission by incorporating financial development, economic growth, industry value added, and agriculture value added in it. This research covers the 37 years of panel data of five countries, i.e., India, the Philippines, Egypt, Pakistan, and Bangladesh, from 1980 to 2016. The data were collected from the World Bank database. The panel cointegration technique and panel autoregressive distributive lag (ARDL) model have been employed to check long-run relationships. The estimated result of the panel cointegration approach confirms the existence of a long-run relationship among remittances received, financial development, economic growth, industry value added, agriculture value added, and CO2 emission. The findings of the study indicate that an increase in received remittances, economic growth, and value-added agriculture help in mitigating carbon emissions from the selected panel countries. However, improving the financial system and adding more industries result in the high emission of CO2. On the contrary, the short-run ARDL estimation shows that CO2 emission increases at a significant level with the increase of remittances inflow and agriculture value added, while in the case of financial development, economic growth, and industry value added, this increasing effect in CO2 is at an insignificant level. Moreover, dynamic ordinary least square (DOLS) is used in this study for robust analysis and found the same long run result like ARDL. Additionally, this study also provides some important recommendations to economic policymakers to reduce CO2 emission in the selected remittance-receiving countries.

One of the important ways to the efficiently use of low-grade thermal energy is the adsorption refrigeration technology. However, it has some drawbacks such as low specific cooling power and coefficient of performance, especially under using the conventional adsorption pairs. Therefore, new adsorption pairs are tested in solar adsorption ice-maker and compared with other conventional pairs data from open literature to find the tendency of improving the solar adsorption ice-maker performance. The experimental test rig has been built in Upper Egypt in Qena City. Four different new adsorption pairs of granular activated carbon/R-410A, granular activated carbon/R-511A, Maxsorb III/R-410A, and Maxsorb III/R-511A are used. It is demonstrated that Maxsorb III/R-511A pair based solar adsorption ice-maker produced the highest values for specific cooling power, coefficient of performance, and ice production per 1 kg of adsorbent of approximately 226.7 W/kgₐdₛ, 0.197, and 1.96 kg/kgₐdₛ, respectively. While granular activated carbon/R-410A based solar adsorption ice-maker produced the lowest values of ice production per 1 kg of adsorbent and coefficient of performance of 1.38 kg/kgₐdₛ and 0.104, respectively. Moreover, it can be concluded that the tested pairs are feasible to be used in solar adsorption ice-maker systems, especially in such hot climate of Upper Egypt for food and vaccine preservation and storage.

Oil pollution is a worldwide concern due to the increasing rate of offshore oil production and transport. As the Nile Delta coast is adjacent to the main route of oil transport through the Suez Canal, accidental oil spills along the offshore region may have a tremendous impact on the coastal waters. If the oil slicks reach the coast, the impact should also be significant. This study aimed to map the oceanographic parameters that may affect oil pollution dispersion along the offshore zone of the Nile Delta using geographic information system (GIS) techniques. Oceanographic data (wave patterns, bathymetry data, sea surface temperature (SST), chlorophyll content, phytoplankton concentration, and organic carbon concentration) were used to analyze the characteristics of water at the onset of oil pollution to interpret the dispersion of the oil slick once discharged into the seawater. The results showed that SSTs and the depth of the coastal zone primarily influence the distribution of the other parameters.