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Introduction: Environmental exposure to indoor dust is known to be associated with myriad health conditions, especially among children. Established routes of exposure include inhalation and non-dietary ingestion, which result in the direct exposure of gastrointestinal epithelia to indoor dust. Despite this, little prior research is available on the impacts of indoor dust on the health of human gastrointestinal tissue. Methods: Cultured human colonic (CCD841) cells were exposed for 24 h to standard trace metal dust (TMD) and organic contaminant dust (OD) samples at the following concentrations: 0, 10, 25, 50, 75, 100, 250, and 500 µg/mL. Cell viability was assessed using an MTT assay and protease analysis (glycyl-phenylalanyl-aminofluorocoumarin (GF-AFC)); cytotoxicity was assessed with a lactate dehydrogenase release assay, and apoptosis was assessed using a Caspase-Glo 3/7 activation assay. Results: TMD and OD decreased cellular metabolic and protease activity and increased apoptosis and biomarkers of cell membrane damage (LDH) in CCD841 human colonic epithelial cells. Patterns appeared to be, in general, dose-dependent, with the highest TMD and OD exposures associated with the largest increases in apoptosis and LDH, as well as with the largest decrements in metabolic and protease activities. Conclusions: TMD and OD exposure were associated with markers of reduced viability and increased cytotoxicity and apoptosis in human colonic cells. These findings add important information to the understanding of the physiologic effects of indoor dust exposure on human health. The doses used in our study represent a range of potential exposure levels, and the effects observed at the higher doses may not necessarily occur under typical exposure conditions. The effects of long-term, low-dose exposure to indoor dust are still not fully understood and warrant further investigation. Future research should explore these physiological mechanisms to further our understanding and inform public health interventions. 

and cover changes impact the soil and water quality which are critical for environmental and human health. The goal of this study is to evaluate whether the land cover change along the Tigris River, one of the largest rivers in the Middle East, is causing any heavy metal contamination. The objectives of this study were: (1) To analyze the metal concentrations in the water and soil samples along the Tigris River and (2) identify and map the land cover changes of the Baghdad district. A total of nine water and soil samples were collected from three different Tigris River (TR) sampling locations, namely Gherai´at (TR1), Bab Al Moatham Bridge (TR2), and Karada-Masbah (TR3). Surface soil and water samples were collected, and analyzed for various metal concentrations. Landsat satellite imagery from 1984 and 2018 were analyzed and compared for land cover changes. Our water sample analysis revealed that As, Cd, Cr, Cu, Pb and Zn remained low and are within the permissible limit of WHO standards. Soil samples showed that Cu, and Pb concentrations in TR1 and TR2, respectively were higher compared to other locations. The metal concentrations in both water and soil samples at the sampled locations were at safe levels. Remote sensing analysis revealed that the water surface in the study area increased by about 5.3% while the vegetative surface decreased by 10.3% during the period of 1984 to 2018. Water and vegetative cover increased further in the south of Baghdad, along the Tigris River, compared to the north. The impact of land cover changes and increase in soil metal concentrations are higher on TR2 and TR3 locations. Environmental chemical analysis coupled with geospatial data helps to monitor the impact of land cover changes on water and soil quality by identifying areas vulnerable to change.