Acute and chronic health problems are expected due to exposure to high levels of formaldehyde. The aim of the current study was to evaluate the outdoor and indoor levels of formaldehyde in Cairo in order to assess the carcinogenic and non-carcinogenic risks as a result of exposure to formaldehyde. Formaldehyde concentrations were measured outdoors and indoors at five residential sites in Cairo, Egypt. The samples were taken during the day (8 AM to 6 PM) and at night (8 PM to 6 AM) for 10 hours during winter and summer seasons of 2018/2019. Chronic daily intakes (CDI), cancer risk (R) and hazard quotient (HQ), were estimated to assess health risks from exposure to formaldehyde. Outdoor average concentrations of formaldehyde at the selected sites were 24.6 and 22.8 µg/m³ in summer and winter, respectively, which exceeded the value of 15 ppb (18.3 µg/m3) set as an indicator for urban environment. Indoor HCHO concentrations are still far lower than the effective short-term exposure levels of HCHO between 0.5 and 1 ppm (0.62-1.23 mg/m3) which could lead to irritation of throat, nose and eyes. Newly apartments with newly furnished can be a stronger source for formaldehyde emissions than the ambient sources.The I/O ratios of formaldehyde were above one which demonstrated that the sources in the indoor environment are prevalent at the investigated sites.The outdoor cancer risk values did not exceed the “alarm level” (R > 1 × 10–4) for formaldehyde, while in living rooms and kitchens they exceeded the “alarm level” by 30% and 55% in winter and summer, respectively. The results indicated that the levels of airborne and inhaled formaldehyde in Cairo residences should not be underestimated. The current study can help regulatory agencies to establish guidelines for formaldehyde concentration in indoor air.

This study estimates the association between respiratory outcomes among employees of a secondary aluminum plant and airborne pollutants. Additionally, it looks into the relationship between pulmonary dysfunction in workers and X-Ray repair cross-complementing one (XRCC1) gene polymorphisms. 110 exposed workers and 58 non-exposed workers were enrolled in the study. Measurements were conducted on sulfur dioxide (SO₂), nitrogen dioxide (NO₂), and particulate particles. Pulmonary function was tested. Eosinophil cationic protein (ECP), C-reactive protein (CRP), matrix metalloproteinase-1 (MMP-1), interleukin 6 (IL6), granulocyte-macrophage colony-stimulating factor (GM-CSF), XRCC1 protein, and genotyping of XRCC1 gene polymorphisms were examined. The annual average concentrations of particulate matter (PM_2.5, PM₁₀), total suspended particulates (TSP), SO₂, and NO₂ were lower than the permissible limit. The areas around ovens, evaporators, and cold rolling mills exhibited the highest amounts. The majority of employees in these departments had impaired lung function. Prolonged exposure was associated with a significant decrease in forced expiratory volume in 1 s (FEV1%) and forced vital capacity (FVC%) among the exposed group (p = 0.001 & 0.04, respectively). Serum XRCC1 levels were significantly higher among exposed workers (p = 0.02). Inflammatory biomarkers showed no statistically significant differences between groups. Aluminum workers are at risk of developing respiratory disorders. The level of serum XRCC1 may serve as a potential biomarker for detecting susceptible workers.

This study aims to determine the potential impact of heavy metal pollution on plant cultivation and its proteins content. This study presents the effect of pollution with some heavy metals (Pb, Ni, Cd, Zn) on total protein content during the vegetative growth stages of maize (Zea mays L.) plant via environmental indicators. Pb, Ni, Cd, and Zn were measured in deposited dust, surface soil, and Maize plant (Zea mays L.) samples collected from two sites in Benha city, Egypt, as well as proteins in maize plant were evaluated. Additionally, Ecological indices [geo-accumulation index (Igeo), pollution load index (PLI) and contamination factor (CF)] were determined. The obtained data showed that, the average rate of dust falls in Benha city, Egypt reached to 15.41 g/m2 /month. The concentration levels of metals are arranged in the order of: Zn > Ni > Cd > pb in the deposited dust and maize plant, while they are arranged in the order of: Zn > Ni > pb > Cd in the surface soil. The wind rose of the meteorological parameters in Benha city shows that site 1 is on up wind direction, while site 2 is located down wind. Consequently, site 2 had higher deposition rates and higher levels of heavy metals than site 1. Furthermore, the total protein content was extremely affected as a result of the heavy metals stress, where the protein content significantly decreased in Site 2 plants compared to those of Site 1. Ecological indices showed that deposited dust and surface soils at site 2 were moderately to heavily pollute with Cd, while they were unpolluted with other metals (Pb, Ni, and Zn).