Search Results (28)

Tobacco smoke is an important pollutant that causes over 8 million deaths each year, of which, 1.3 million deaths are attributed to second-hand smoke. Third-hand smoke refers to the chemical emitted from smoking that remains in the air, dust, and on the surfaces after smoking has stopped. These substances, which are deposited or adsorbed on indoor surfaces and dust and can be re-emitted into the indoor air continually, leading to human exposure over an extended period. The properties of the third-hand smoke chemicals and indoor surfaces are key factors influencing their indoor behaviors and human exposure. Additionally, the substances on surfaces can react with atmospheric oxidants to form secondary pollutants. For instance, nicotine in third-hand smoke reacts with atmospheric oxidants (ozone, nitrous acid, and hydroxyl radicals) to produce other toxic, carcinogenic substances, which may be more toxic, further increasing the risk to human health. This review aims to address three key questions: (1) What are the components of third-hand smoke? (2) How does third-hand smoke adsorb and desorb on/from indoor surfaces, and undergo chemical transformation? (3) How is exposure to third-hand smoke related to human health effects? Therefore, we conducted a comprehensive review of the chemical composition of third-hand smoke, its adsorption and desorption on indoor surfaces, chemical transformations indoors, and health effects, The chemical composition of third-hand smoke is complex, containing various toxic substances, carcinogens, and heavy metals. This review provided suggestions to prevent exposure to third-hand smoke. Full article

An integral part of daily dental practice is preparing and polishing placed composite restorations. When these procedures are performed, significant amounts of composite dust are released from the grinding material. This systematic review aims to enhance the existing body of knowledge, encourage further dialogue, and expand the understanding of composite dust and its related risks. Following inclusion and exclusion criteria, twelve studies were included. Several studies highlight that composite dust contains nanoparticles capable of deep lung penetration, posing significant health risks to both dental staff and patients. Inhalation of composite dust can lead to respiratory diseases such as pneumoconiosis. Studies have shown that water cooling during composite grinding reduces dust emissions but does not eliminate them completely. Researchers suggest that thermal degradation of the composite material, not just filler particles, may be the source of the nanoparticles. In vitro studies have shown the toxicity of composite dust to bronchial and gingival epithelial cells, especially at high concentrations. Further research is needed on the health effects of composite dust and the development of effective methods to protect staff and patients. Full article

A nanomaterial life-cycle risk assessment (Nano LCRA) was conducted for second-generation functionalized cellulose nanomaterials (CNs) in five case studies, including applications in water filtration, food contact packaging (including as an additive and coating), and food additives, to identify and prioritize potential occupational, health, consumer, and environmental risks. Exposure scenarios were developed and ranked for each product life-cycle stage. A Safer-by-Design Toolbox (SbD Toolbox) representing a compendium of high-throughput physical, chemical, and toxicological new approach methodologies (NAMs) was used for a screening-level hazard assessment. Overall, risks identified for the CN-enabled products were low. Of the exposure scenarios, occupational inhalation exposures during product manufacturing and application ranked the highest. Despite differences in chemistry and morphology, the materials behaved similarly in oral, dermal, and inhalation models, supporting their grouping and read-across. The screening-level hazard assessment identified potential lung inflammation associated with CN exposure, and a review of the literature supported this funding, suggesting CNs behave as poorly soluble, low-toxicity dusts with the potential to irritate the lung. Key research gaps to reduce uncertainty include evaluating long-term, low-dose exposures typical of the workplace, as well as the potential release and toxicity of CN-containing composite particles. Full article

Dust containing lead and zinc is a harmful contaminant, which causes serious harm to the natural environment and human health. At present, it is believed that the microscopic morphology of lead-zinc dust is intimately related to its biological toxicity. Chemical composition serves as a pivotal factor influencing the structural characteristics of dust. However, research on the impact of chemical composition variations on the microscopic morphology of dust containing lead and zinc remains inadequate. The particle size analysis reveals that as PbO content increases and ZnO content decreases, the particle size of the dust diminishes, but some samples exhibit a larger agglomeration structure. Combined with the results of the box number method, it is evident that at lower magnifications, an increase in PbO content leads to a decrease in image complexity and a loosening of aggregated structures. The similarity in pile shapes amplifies this trend, resulting in a decline in the box-counting dimension (D value) within the PbO/ZnO ratio range of 26.45 to 138, accompanied by an inverse change in the corresponding goodness of fit R-sq value. At the observation multiple of 30,000 times (30 K), smaller particles within the sample become visible, and the presence of relatively larger particles and complex sizes enhances the fractal characteristics of the sample, leading to a higher D value. Within the PbO/ZnO ratio range of 90/10 to 99/1, a coupling relationship exists between the chemical composition of the sample and the morphology of the dust. Specifically, the PbO/ZnO ratio exhibits a positive correlation with the D value. Conversely, the diversity of corresponding fractal features is negatively correlated with the D value. When the PbO content surpasses 99%, this correlation weakens, and the diversity of graphical representations displays an alternating pattern of growth and decrease. Notably, the D value and the goodness of fit (R-sq) of the D value are negatively correlated, indicating that as the complexity of the graph increases, the goodness of fit decreases. Full article

In both developed and developing countries, atmospheric pollution with particulate matter (PM) remains an important issue. Despite the health effects of poor air quality, studies on air pollution are often limited by the high costs of continuous monitoring and the need for extensive sampling. Furthermore, these particles are often enriched with potentially toxic trace elements and organic pollutants. This study evaluates both the composition of atmospheric dust accumulated during a certain timespan on Hedera helix and Senecio cineraria leaves and the potential for their use as bio-monitors. The test plants were positioned near automatic air quality monitoring stations at four different sites with respectively high, moderate and low traffic intensity. The gravimetric deposition of PM10 and PM2.5 on leaves was compared with data recorded by the monitoring stations and related to the weather conditions reported by Argentina’s National Meteorological Service. To determine the presence of trace elements enriching the PM deposited on leaves, two analytical techniques were applied: XRF (not destructive) and ICP (destructive). The results indicated that only in the unpaved street location (site 2) did PM10 and PM2.5 concentrations (90 µg m⁻³ and 9 µg m⁻³) in the air exceed more than five times WHO guidelines (15 µg m⁻³ and 5 µg m⁻³). However, several trace elements were found to be enriching PM deposited on leaves from all sites. Predominantly, increased concentrations of Cd, Cu, Ti, Mn, Zn and Fe were found, which were associated with construction, traffic and unpaved street sources. Furthermore, based on its capability to sequester above 2800 µg cm⁻² of PM10, 2450 µg cm⁻² of PM2.5 and trace elements, Senecio cineraria can be taken into consideration for adoption as a bio-monitor or even for PM mitigation. Full article

To mitigate dust pollution generated during various stages of construction activities and reduce the environmental and health hazards posed by airborne dust, this study utilized hydroxyethyl cellulose, glycerol, and isomeric tridecyl alcohol polyoxyethylene ether as raw materials to formulate a composite chemical dust suppressant. The properties of the dust suppressant were characterized through analysis. Employing single-factor experiments, the optimal proportions of the binder, water-retaining agent, and surfactant for the composite dust suppressant were determined. Subsequently, a response surface model was established, and, after analysis and optimization, the optimal mass ratios of each component in the composite dust suppressant were obtained. Under optimal ratios, the physicochemical properties and wind erosion resistance of the composite dust suppressant were analyzed. Finally, the practical application of the suppressant was validated through on-site trials at a construction site. This study revealed that the optimal formulation for the dust suppressant was as follows: 0.2% hydroxyethyl cellulose, 2.097% glycerol, 0.693% isomeric tridecyl alcohol polyoxyethylene ether, and the remainder was pure water. The suppressant is non-toxic, non-corrosive, environmentally friendly, and exhibits excellent moisture retention and bonding properties compared to water. The research findings provide valuable insights for addressing dust pollution issues on construction sites. Full article

Environmental pollution from industrial factories via air deposition is an urgent problem worldwide. Phosphate fertilizers, derived from rock phosphate, are characterized by the presence of potentially toxic elements, such as Zn, Co, Pb, Ni, Cr, Mn, Fe, and Cu, which are dispersed in the form of solid dust-like materials from the pipes of the factory. This study aimed to investigate the effects of airborne industrial emissions on the chemical and biochemical compositions of cotton grown in the immediate vicinity of a fertilizer factory in Uzbekistan. The composition of airborne dust deposited on the plants, the chemical composition of the cotton leaves before and after washing, as well as that of above- and below-ground plant organs, and their protein contents were determined. The concentrations of macro- and microelements in the leaves and roots were determined using an atomic absorption spectrophotometer. The fluorine contents in the leaves and in the roots were determined using a fluorine-selective electrode. The radius of dispersion of industrial emissions in the air was best described by measuring the fluorine contents in washed and unwashed cotton leaves. The relationships among P, K, Mg, Ca, S, F, and Mn in plant roots and leaves as a function of distance from the pollutant source were analyzed. Based on the fluorine contents in washed and unwashed cotton leaves, the two following zones of technogenic pollution were distinguished: the zone < 5 km from the factory, with high technogenic pollution, and the zone > 5 km from the factory, with moderate technogenic pollution. It was found that the resistance of cotton to air pollution from industrial emissions is determined by the ability of cotton plants to neutralize toxic compounds by increasing the influx of alkaline earth metals into the affected tissues. This study showed the possibility of growing cotton at a distance of >5 km from the fertilizer factory. It is strongly recommended to analyze the chemical composition of plants located in a highly polluted zone only after the dust particles have been washed off of the plant’s surface. Despite the resilience of cotton to industrial pollution, the monitoring of areas identified as pollution zones is recommended. Full article

Photocatalytic coatings can degrade volatile organic compounds into non-toxic products, which has drawn the attention of scholars around the world. However, the pollution of dust on the coating adversely affects the photocatalytic efficiency and service life of the coating. Here, a series of TiO₂-polyfluoroalkoxy (PFA) coatings with different contents of PFA were fabricated by suspension plasma spraying technology. The results demonstrate that the hybrid coatings contain a large number of circular and ellipsoidal nanoparticles and a porous micron-nano structure due to the inclusion of PFA. According to the optimized thermal spraying process parameters, TiO₂ nanoparticles were partially melted to retain most of the anatase phases, whereas PFA did not undergo significant carbonization. As compared to the TiO₂ coating, the static contact angle of the composite coating doped with 25 wt.% PFA increased from 28.2° to 134.1°. In addition, PFA strongly adsorbs methylene blue, resulting in a greater involvement of methylene blue molecules in the catalyst, where the catalytic rate of hybrid coatings is up to 95%. The presented nanocomposite coatings possess excellent photocatalytic and self-cleaning properties and are expected to find wider practical applications in the field of photocatalysis. Full article

Dental healthcare plays an important role in the overall health of individuals, and the sector is rapidly growing around the world due to increases in population, healthcare facilities, and improved access for economically weaker sections of society. Dental procedures and oral care generate a significant amount of biomedical waste that should be managed in an environmentally safe and sustainable manner. An overview is presented of the current status of dental solid waste management with a focus on waste composition from traditional and emerging dental treatments, new-generation dental materials, waste treatment procedures, and current options. Dental waste can be broadly divided into three categories: infectious waste, non-infectious waste, and domestic-type waste. Infectious waste contains materials contaminated with blood or other infectious mouth fluids, amalgam, and sharps, whereas non-infectious dental waste is devoid of human fluid contamination but can be potentially toxic due to the presence of amalgams, acids, metal dust, resins, etc. Suspended particulates in dental wastewater are another likely source of contamination. Appropriate segregation of this waste is essential for containing infections during waste processing. New-generation dental materials, such as nanomaterials, resin-based composites, and ceramics, are finding increasing applications in a variety of dental procedures as antimicrobial, restorative, and therapeutic agents. While incineration and landfilling have been used for processing traditional dental waste, the presence of novel materials in dental waste raises several additional concerns. Novel single/multistage recycling approaches need to be developed for dental waste towards resource recovery, thus minimizing incineration and landfilling to the extent possible. Full article

This study aimed to investigate the effect of raw waste pine wood dust (Pinus sylvestris) from furniture production on polysaccharide biopolymer film properties. The obtained biocomposite films produced via the casting method were prepared with 20% glycerol and 0%, 5%, 10%, 15%, 20%, and 25% of added wood dust in relation to the dry starch matter. Wood dust composition and particle size distribution analysis were performed. In order to evaluate the material surface properties, tests were carried out using an atomic force microscope (AFM) and a contact angle goniometer. Utilising uniaxial tensile test methodology, the values for both tensile strength and Young’s modulus were determined. In addition, the barrier properties, water solubility index, and colour were also investigated. The research showed that wood dust affected the functional parameters of the obtained biocomposites. A wood dust content increase causes the Young’s modulus value to rise with a progressive decrease in the max. strain. The filler did not change the films’ wetting properties, and each had a hydrophilic surface regardless of the additive amount. The bio-sourced composites obtained were non-toxic and environmentally neutral materials, suitable to be applied in the packaging industry as well as the agriculture sector. Full article

Because of the rising environmental and health concerns associated with atmospheric pollution caused by potentially toxic elements (PTEs), several road dust studies have been performed across the world in recent decades. This paper illustrates the effects of particle size on the PTE contents, mineralogical composition, environmental pollution and health risk assessments in road dust from Barcelona (Spain). The samples were sieved into five size fractions ranging from <45 to 500–800 µm. Although the major mineral contents (tectosilicates, phyllosilicates, and carbonates) were profuse in all fractions, the identified inhalable PTE particles (e.g., Fe, Cr, Cu, Zn, Ni, and REE), with size < 10 µm, were more pervasive in the finest fraction (<45 μm). This is consistent with the concentrations measured: the finest fractions were richer in PTEs than the coarser ones, resulting in a direct correlation with the enrichment factor (EF_x), geo-accumulation (I_geo), and non-carcinogenic (HI) and carcinogenic (CRI) values. I_geo and EF_x values can be appropriate tracers for some common elements (e.g., Zn, Sb, Sn, Cu, and Cr), but they do not seem adequate for anthropogenic particles accumulated at concentrations similar to the geogenic background. Overall, the HI and CRI values obtained in Barcelona were acceptable, reflecting no serious health impacts in the study area, except for Cr. Our results suggest that fine dust particles are a more suitable fraction to conduct pollution and health risk assessments than coarser ones, although the EF_x, I_geo, HI, and CRI threshold values should be redefined in the future to include all emergent pollutants as well. In summary, monitoring programs should include at least the road dust evaluation of <45 µm particles, which can be performed with a simple sieving method, which is both time- and cost-effective. Full article

Urban fugitive dust is a significant contributor to atmospheric PM_2.5 and a potential risk to humans. In 2019, both road dust and construction dust were collected from four cities, including Xi’an, Xianyang, Baoji, and Tongchuan, in Guanzhong Plain, China. Elements, water-soluble ions, and carbonaceous fractions were determined to establish the chemical source profile. High enrichment degrees of Se, Sc, Cl, and Zn in both road dust and construction dust indicated that the industrial system and energy consumption influenced Guanzhong Plain strongly. According to the coefficient of divergence, the two datasets within Xianyang and Tongchuan were similar. Combined with the chemical profile, road dust was affected by more stationary emission sources than construction dust in Xi’an, while biomass burning and vehicle exhaust contributed more to road dust than construction dust in Baoji. Moreover, the health risk of heavy metal was assessed, and corresponding influencing factors were identified. Road dust in all cities showed a non-negligible non-carcinogenic risk for children. Ingestion and inhalation were the main exposure pathways to which As and Co contributed the most, respectively. The land-use regression model revealed that the first-class road in a 100 m radius impacted all high-risk level metals, and the commercial building material and enterprises weakly influenced Co and Pb, respectively. Full article

Excessive exposure to heavy metals induces potential adverse health impacts in humans. More specifically, heavy metals in particulate matter (PM) have a significant impact since PM can penetrate human organs and systems, causing several morbidities. In this work, dust samples were collected from 20 different types of roads in a busy zone in Doha during the winter of 2016–2017, where a higher human exposure rate occurs due to extensive outdoor activities during this time of the year. The elemental composition in terms of the mass concentration of 30 elements was determined in each sample via an energy-dispersive X-ray fluorescence (XRF) spectrometer. Then, the toxicity of six heavy metals in these airborne traffic dust samples was investigated. The heavy metals reported to have a hazardous impact on human health are As, Pb, Hg, Cd, Cr, Co, Ni, Cu, and Zn. The extent of carcinogenic and non-carcinogenic risk impact was assessed using pollution indices and then determining the health risks associated with exposure to heavy metals through inhalation, ingestion, and dermal contact. The non-carcinogenic hazard index analysis results indicate no toxicity for all metals. However, the carcinogenic risk factor results show that only chromium might induce a slight risk for children and adults. In light of this, further research is recommended to investigate more areas in urban Doha where more samples can be collected and analyzed. Full article

The toxicity of particulate matter (PM) is strictly associated with its physical-chemical characteristics, such as size or chemical composition. While these properties depend on the origin of the particles, the study of the toxicological profile of PM from single sources has rarely been highlighted. Hence, the focus of this research was to investigate the biological effects of PM from five relevant sources of atmospheric PM: diesel exhaust particles, coke dust, pellet ashes, incinerator ashes, and brake dust. Cytotoxicity, genotoxicity, oxidative, and inflammatory response were assessed in a bronchial cell line (BEAS-2B). BEAS-2B cells were exposed to different concentrations (25, 50, 100, and 150 μg/mL medium) of particles suspended in water. The exposure lasted 24 h for all the assays performed, except for reactive oxygen species, which were evaluated after 30 min, 1 h, and 4 h of treatment. The results showed a different action of the five types of PM. All the tested samples showed a genotoxic action on BEAS-2B, even in the absence of oxidative stress induction. Pellet ashes seemed to be the only ones able to induce oxidative stress by boosting the formation of reactive oxygen species, while brake dust resulted in the most cytotoxic. In conclusion, the study elucidated the differential response of bronchial cells to PM samples generated by different sources. The comparison could be a starting point for a regulatory intervention since it highlighted the toxic potential of each type of PM tested. Full article

Following population growth and rapid urbanization, West African cities have become major sources of anthropogenic pollution. Additionally, Saharan dust has had a significant impact, representing a potentially toxic mix of sources for the population. This study characterizes the atmospheric composition and its sources in two African capitals, Bamako, Mali and Dakar, Senegal. TSP, PM₁₀ and PM_2.5 samples were collected during the dry season in 2009 when pollution levels were high: chemical analysis included organic carbon (OC), elemental carbon (EC), ions, and metals. PM_2.5 and PM₁₀ concentrations were 5–10 times and 3–8 times higher, respectively, than the 2005 WHO 24 h standards. Using PCA and PMF methodologies, five sources were identified in each city. In Bamako, traffic (motor vehicles and resuspended road dust) was the prevailing source of PM_2.5 and PM₁₀, accounting for 47% and 45%, respectively. Crustal dust was the second most important source (24–30%), followed by solid fuel combustion (16–13%) and secondary aerosols (10–16%). In Dakar, the following sources of PM_2.5 and PM₁₀ are identified: traffic (49%), mineral dust (16–25%), sea salts (15–20%) and industries (10–11%). Our study provides crucial information about the historical change in source characteristics in these two African cities, which can help for future mitigation strategies. Full article