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Biological hazards
Published in Sue Reed, Dino Pisaniello, Geza Benke, Principles of Occupational Health & Hygiene, 2020
Margaret Davidson, Ryan Kift, Sue Reed
Certain bioaerosols can act as irritants, cause airway blockages or stimulate the innate immune system, even when they do not produce an allergic response in the worker. One of the most common symptoms, mucous membrane irritation (MMI), which may appear consistently during the work shift, may take the form of irritation and inflammation of the upper respiratory tract—conjunctivitis, sinusitis, rhinitis, pharyngitis, laryngitis and tracheitis. There may also be a chronic cough or bronchitis (Rusca et al., 2008; Schlosser et al., 2009). Important non-allergenic diseases include non-allergic asthma, inhalation fever and ODTS.
Nanoscale Ceramics
Published in Debasish Sarkar, Nanostructured Ceramics, 2018
Usually, the influence of nanoparticles on human body can be done three ways: Inhalation: Gases and vapors are the most common substances, although inhaled mists, aerosols, fine dust in preference nanoparticles, nanoobjects, their agglomerates, and aggregates may directly injure the pulmonary epithelium at various levels of the respiratory tract, leading to a wide range of tissue damage and disorders from tracheitis and bronchiolitis to pulmonary edema. For example, silicosis is a common disease for industrial workers who are frequently exposed to nanoscale silica-based particles [27].Dermal exposure: Skin comprising of epidermis and dermis, wherein, hair follicles and sweat glands provide pathways across these layers and peripheral blood flowing into the dermis. Intact stratum corneum (protective epidermis layer) provides an effective barrier against viruses, bacteria, and atmospheric toxic components. Although, this barrier is not absolutely impervious and theoretically very small particles can diffuse across the stratum corneum via cellular and/or intercellular pathways. The damaged barrier can facilitate permeation of foreign particles through skin. For example, the subchronic skin exposures to TiO2 (in sun protection cosmetics) could induce inflammation of the epidermis, leading to effects such as focal parakeratosis and spongiosis, whereas chronic exposures to TiO2 may accelerate skin aging [28].Ingestion: Use of biomedicine made of polymeric, solid lipid, hydrogels, metal, and ceramic nanosystems are growing exponentially, as these enhance the treatment efficacy and reduce the side effects. However, unwanted ingestion of nanoparticles, overdose, and noncompeting nanomedicine may be the reason of gastrointestinal diseases that affect any part of the gastrointestinal tract including acute, chronic, recurrent, functional disorders, or liver damage [29]. Thus, the parameters such as shape, size, surface chemistry, and geometry of nanoparticles are also important to encounter in the designing of a nanocarrier.
Association between short-term exposure to air pollution and respiratory diseases among children in China: a systematic review and meta-analysis
Published in International Journal of Environmental Health Research, 2022
Junyao Zheng, Xiao Yang, Siqi Hu, Yikai Wang, Jinlin Liu
This systematic review and meta-analysis showed that short-term exposure to air pollutants in China had general positive impacts on the excess risk of outpatient visits due to children’s respiratory diseases. The results showed that different pollutants had different impacts on respiratory diseases in Chinese children. On the one hand, we noted that PM2.5 had a greater adverse effect on outpatient visits for respiratory diseases than PM10. The widely accepted theories about the pathogenesis of PM2.5 and PM10 include direct damage, free radical oxidation damage, immune-inflammatory damage, and damage to genetic material (Ye et al. 2016). One of the potential interpretations is that PM2.5 has a smaller particle size and larger surface area than PM10. Heavy metal ions, organic pollutants, acid oxides, bacteria, and viruses in the air easily adhere to the surface (Zhai et al. 2014), which is very harmful to children’s respiratory system (Li and Yu 2010). Most PM10 is absorbed by the ciliated mucus layer of the upper respiratory tract, pushed to the pharynx through ciliated movement, and then excreted with coughing or sneezing (Zhu and Yang 2008; Tecer et al. 2008). On the other hand, for gaseous air pollutants, the influence of NO2 is much greater than that of SO2 and O3. Factors that could potentially explain this finding may include that NO2 is difficult to dissolve in water, so it is more likely to invade the deep trachea of the respiratory tract and induce tracheitis (Zhang and Cui 2001). Therefore, more attention should be given to the adverse effects of PM2.5 and NO2.