Particulate Matter Density Research Articles

Short-term particulate matter contamination severely compromises insect antennal olfactory perception

The consequences of sub-lethal levels of ambient air pollution are underestimated for insects, for example, the accumulation of particulate matter on sensory receptors located on their antennae may have detrimental effects to their function. Here we show that the density of particulate matter on the antennae of houseflies (Musca domestica) collected from an urban environment increases with the severity of air pollution. A combination of behavioural assays, electroantennograms and transcriptomic analysis provide consistent evidence that a brief exposure to particulate matter pollution compromises olfactory perception of reproductive and food odours in both male and female houseflies. Since particulate matter can be transported thousands of kilometres from its origin, these effects may represent an additional factor responsible for global declines in insect numbers, even in pristine and remote areas.

The COVID-19 incidence in Italian regions correlates with low temperature, mobility and PM10 pollution but lethality only with low temperature.

Background: The aim was to verify whether the density of particulate matter (PM10), the climate, and the mobility of people can influence the pandemic in the 19 regions and in the two autonomous Italian provinces as incidence rate and lethality.Design and Methods: The incidence rates per 100,000 inhabitants and the case fatality ratio (CFR) (dependent variables) in all Italian regions were calculated in January 2021 at John Hopkins University Coronavirus Center. The independent variables were: Minimum average temperatures in the same month (January) of 2020; average pollution of PM10 in the air in each region in the last year available reported on a 0-10 scale to 0 = total absence of PM10 to 10 maximum pollutions; number of places in hotels occupied per inhabitants in 2020. Linear regression and Multiple Regression Analysis were carried out.Results: The spread of the COVID-19 in the Italian regions seems to be related to pollution of PM10, the number of beds occupied in hotels (as an index of mobility and temperature (indirect correlation). On the contrary, the CFR correlates inversely with temperature but not with pollution. Measuring the concomitant effect of two independent variables by means of Multiple Regression Analysis, temperature and pollution show a synergistic effect on COVID-19 incidence.Conclusions: The study seems to confirm the literature on the influence of temperature on the lethality of COVID-19 but adds the new results of an inverse relationship between the spread of the virus and low temperature in regions between the Mediterranean area (which includes southern Italy and Sicily and Sardinia islands) and the cold European temperate zone which includes the northern regions under the Alps. A new date also concerns the summation effect of the risk between cold weather and PM10 air pollution was found. Due to several methodic weakness the study has an exploratory than conclusive relevance. Significance for public health This paper has an exploratory value because a homogeneous population is taken into account. Presented results that basically contain the combined effect of cold climate (and pollution by PM10) on COVID-19 must be confirmed.

Investigating the Relationship Between Air Quality and COVID-19 Transmission

It is hypothesized that short-term exposure to air pollution may influence the transmission of aerosolized pathogens such as COVID-19. We used data from 23 provinces in Italy to build a generalized additive model to investigate the association between the effective reproductive number of the disease and air quality while controlling for ambient environmental variables and changes in human mobility. The model finds that there is a positive, nonlinear relationship between the density of particulate matter in the air and COVID-19 transmission, which is in alignment with similar studies on other respiratory illnesses.

Numerical Simulation of the Distribution of In Situ Cigarette Combustion-Generated Particulate Matter

This paper has established a two-dimensional (2D) mathematical model for the generation, growth, and deposition of cigarette total particulate matter (TPM) in the smoldering state. The model has covered the chemical reactions and mass transfer as well as the mechanism of generation, flow, and condensation of particulate matter inside a burning cigarette. Cigarette smoke was generated by puffing under a constant pressure, and the pressure of the filter outlet was −274 Pa. The peak of the concentration of particulate matter was spatially overlapped with the peaks of pyrolysis and oxidation. Pertaining to the cross section of the cigarette at the same axial position, the peak of the diameter of particulate matter along the radial distribution first appeared in the zone near the edge of the cigarette cross section, and then gradually moved to the center of the cigarette with the cigarette smoke moving away from the combustion cone. The maximum number density of particulate matter calculated by the 2D mathematical model at the same axial position of the cigarette and the corresponding particle diameter, as well as the filtration efficiency of the filter rod, are in good accordance with the experimental data reported in previous studies.

Airborne Particulate Matter Density in Traditional Bakeries of Saveh, Central of Iran, in 2020

Introduction: High concentration of inhalable airborne particles can increase the risk of lung disease in exposed people. This study aimed to determine the respirable particulate matter (PM5) concentration in traditional bakeries of Saveh in 2020. Materials and Methods: This cross-sectional descriptive study was conducted among 25 bakeries where the samples were collected by cyclone and teflon filter equipped by air sampling pump. Later, the respirable particulate matter concentration was measured using gravimetric method. The collected PM5 was scanned using a FTIR (Fourier-transform infrared spectroscopy) with regard to flour dust. In addition, size and shape of the collected PM5 were analyzed using a scanning electron microscope (SEM). Results: Findings showed that the Lavash bakery had the highest PM5 concentration (9.15 mg/m3) in comparison with two other bakeries (Sangak and Barbari). However, an inverse relationship was observed between RH and particle concentration. In addition, the results demonstrated that increasing RH decreased the particle concentration, but the relationship was not significant (P = 0.052, Spearman's rho = -0.393). Furthermore, Lavash bakery had the lowest average size of PM5 (0.63 ± 0.32 μm). However, the FTIR scans confirmed that the flour dust had the predominant amount of PM5. Conclusion: Based on the findings, the density of respirable PM5 has a high level in Saveh bakeries and workers are exposed to high levels of PM.

Effect of Intraocular Pressure on Aerosol Density Generated by Noncontact Tonometer Measurement.

Aerosols generated by a noncontact tonometer (NCT) were quantified. There was a positive correlation between aerosols and intraocular pressure (IOP), and the concentration of aerosols beside the air jet port was the highest. To investigate the effects of IOP on the aerosol density generated during the use of an NCT and provide references and suggestions for daily protection of ophthalmic medical staff during the coronavirus disease-19 (COVID-19) outbreak. This cross-sectional clinical trial included 214 eyes of 140 patients from a hospital in Wenzhou city, Zhejiang Province. All subjects' IOPs were measured by an NCT (39 eyes with low IOP, 90 eyes with normal IOP, 37 eyes with moderately high IOP, and 48 eyes with very high IOP) between March 7 and June 17, 2020. The density of particulate matter (PM) 2.5 and PM10 generated during the process of IOP measurement with an NCT was analyzed. IOP values were recorded simultaneously. The aerosols generated during different IOP measurements were plotted in scatter plots. PM2.5 was generated more at the air jet port of the tonometer during the process of IOP measurement (H=2.731, P=0.019). Larger quantities of PM2.5 and PM10 were generated when the IOP was higher, and these differences were statistically significant (PM2.5: H=119.476, P<0.001; PM10: H=160.801, P<0.001). Linear correlation analysis with one variable demonstrated that IOP had significantly positive correlations with PM2.5 (r=0.756, P<0.001) and PM10 (r=0.864, P<0.001). Aerosols can be generated while using an NCT to measure IOP, and aerosols and IOP are positively correlated. Patients with moderately high IOP or very high IOP tend to generate more aerosols during the IOP measurement. The concentration of aerosols beside the air jet port was the highest.

Modeling and Analysis of the Population Density Dependent Industrial Emissions of Toxic Air Pollutants and Their Control by External Species Sprayed in the Atmosphere

It is well known that the human health is adversely affected by toxic air pollutants such as sulfur dioxide, nitrous oxide etc. present in the atmosphere. The removal of such pollutants from the atmosphere is, therefore, very much desirable. In this paper, a nonlinear mathematical model is proposed to study the population density dependent industrial emission of toxic air pollutants in the atmosphere and their removal by spraying liquid (water droplets) and particulate matter. In the modeling process, five variables are considered, namely; the cumulative concentration of toxic air pollutants, the density of human population affected by the toxic pollutants, the density of industrialization which is population density dependent, the number density of liquid droplets sprayed in the environment and the density of particulate matter sprayed in the environment. It is assumed that the emissions of toxic air pollutants are linearly related to the density of industrialization, the growth rate of which is directly proportional to the density of human population. It is also assumed that the growth rate of externally sprayed species in the environment is directly proportional to the concentration of toxic air pollutants in the environment. The model is analyzed using stability theory of nonlinear differential equations and numerical simulations. The model analysis shows that as the rate of spray of external species in the environment increases, the cumulative concentration of toxic air pollutants decreases. It is also found that as the rate of removal of toxic pollutants increases, the cumulative concentration of toxic air pollutants in the environment decreases. The effect of toxic air pollutants is observed to decrease the density of human population. The numerical simulation confirms analytical results.

Density of Particulate Matter (PM10) Effect by Cement Industry in Rawang, Selangor Darul Ehsan

Cement industry is one of the main sources of particulate matter (PM). This study is aimed to identify the distribution pattern of density PM production in Rawang. This paper presents comparison of samples in terms of several weather parameters in which the temperature, wind velocity and humidity. This survey was carried out in the region of Rawang using the primary and secondary data. The primary data was obtained from the field observation of PM10 and PM2.5, temperature, humidity and wind velocity in Rawang within 11 observation site locations. The secondary data was obtained from several published documents, articles and journals. The data were analyzed using descriptive statistics which includes mean, median, maximum, minimum, and standard deviation. Finding shows that the average concentration in the central location of the study increases in both parameters which refers to PM10 of 119.31 µg/m3 and PM2.5 of 35.44 µg/m3. This indicated that the level of particles concentration in the region of Rawang was critical

Performance and Emission analysis of optimal DEE blended Pongamia pinnata L. biodiesel fuelled to EGR coupled Low Heat Rejection (LHR) Diesel Engine

To enhance the engine thermal efficiency and simultaneous decrease of emissions, an experimentation was done with 10% constant rate of exhaust gas recirculation (EGR) coupled low heat rejection (LHR) diesel engine developed via 8 YSZ (8% mol. yttria-stabilized zirconia) ceramic material coated cylinder head and liner fuelled by optimal blend B85A15 by vol. (Karanja based biodiesel 85% + additive diethyl ether 15%). Experiments were carried out on the regular engine (RE) and LHR engine fuelled by test fuels (diesel and blend B85A15) at different loads (0%, 20%, 40%, 60%, 80% and 100%) and Injection timings (30° BTDC to 34° BTDC). From the results, it was found that advancement of injection timing significantly improved all the investigated parameters except NOx for both the engines and in comparison the optimum results were 6.5% enhancement in brake thermal efficiency (BTE) with the reduction of 4.5% in brake specific energy consumption (BSEC), 44% in particulate matter density and 18.5% in NOx emissions found for LHR engine fuelled by B85A15 at 33° BTDC with an 80% load compared to RE with diesel. The optimum configuration of RE found to be diesel fuel at injection timing 31° BTDC with 80% load.

Correlation analysis of lung cancer and urban spatial factor: based on survey in Shanghai.

The density of particulate matter (PM) in mega-cities in China such as Beijing and Shanghai has exceeded basic standards for health in recent years. Human exposure to PMs has been identified as traceable and controllable factor among all complicated risk factors for lung cancer. While the improvement of air quality needs tremendous efforts and time, certain revision of PM's density might happen associated with the adjustment of built environment. It is also proved that urban built environment is directly relevant to respiratory disease. Studies have respectively explored the indoor and outdoor factors on respiratory diseases. More comprehensive spatial factors need to be analyzed to understand the cumulative effect of built environment upon respiratory system. This interdisciplinary study examines the impact of both indoor (including age of housing, interval after decoration, indoor humidity etc.) and outdoor spatial factors (including density, parking, green spaces etc.) on lung cancer. A survey of lung cancer patients and a control group has been conducted in 2014 and 2015. A total of 472 interviewees are randomly selected within a pool of local residents who have resided in Shanghai for more than 5 years. Data are collected including their socio-demographic factors, lifestyle factors, and external and internal residential area factors. Regression models are established based on collected data to analyze the associations between lung cancer and urban spatial factors. Regression models illustrate that lung cancer presents significantly associated with a number of spatial factors. Significant outdoor spatial factors include external traffic volume (P=0.003), main plant type (P=0.035 for trees) of internal green space, internal water body (P=0.027) and land use of surrounding blocks (P=0.005 for residential areas of 7-9 floors, P=0.000 for residential areas of 4-6 floors, P=0.006 for business/commercial areas over 10 floors, P=0.005 for business/commercial areas of 7-9 floors, P=0.043 for business/commercial areas of 4-6 floors). Indoor spatial factors include age of housing (P=0.003) and indoor humidity (P=0.000). The findings support the hypothesis that both indoor and outdoor spatial factors are independently associated with lung cancer incidence. Certain principles based on the modeling results are proposed to revise the criteria for lung cancer screening of high-risk individuals. It also provides empirical evidence for urban planning and design to improve built environment with more thorough consideration of respiratory health.

Distribution of the invasive Caprella mutica Schurin, 1935 and native Caprella linearis (Linnaeus, 1767) on artificial hard substrates in the North Sea: separation by habitat

Studying offshore natural and artificial hard substrates in the southern North Sea (51oN–57oN/1oW–9oE), the invasive introduced Japanese skeleton shrimp Caprella mutica Schurin, 1935 was found to co-exist with the native Caprella linearis (Linnaeus, 1767) only on near-shore locations that had an intertidal zone (e.g., wind farm foundations). In contrast, on far offshore and strictly subtidal locations, such as shipwrecks and rocky reefs, only C. linearis was found. Based on these exploratory observations, we hypothesised that artificial structures that are only subtidal are inhabited exclusively by C. linearis, and never by C. mutica. To test this hypothesis and understand factors driving each species’ habitat preferences, habitat suitability models were constructed using generalised additive models, based on samples collected in 2013–2015 from offshore gas platforms, buoys, shipwrecks, and rocky reefs and combined with data from other published and unpublished surveys (2001–2014). The models showed that the presence of C. mutica is explained by the availability of intertidal and floating hard substrates, suspended particulate matter density (SPM), mean annual sea surface temperature, salinity, and current velocity. The C. linearis model included subtidal hard substrates, SPM, salinity, temperature, and current velocity. The modelled distributions showed a significant difference, demonstrating that C. linearis’ habitat preference does not fully overlap with that of C. mutica. Thus, the native and alien Caprella species are likely to be able to co-exist in the North Sea.

Effect of forage particle length on rumen digesta load, packing density and voluntary feed intake by sheep

The effect of forage particle length (4 to 101 mm) on packing density of oesophageal extrusa was investigated following ingestion of chopped wheaten hay by sheep. Packing density of oesophageal extrusa from 4 mm hay was greater than that from hay 21 mm and longer; the difference was associated with smaller particle size and a lower modulus of fineness. There was a significant positive correlation between the intake rate of hay by individual sheep and size of extrusa particles for three of the five forage lengths. The effect of packing density of ingested forage on rumen digesta load and voluntary intake was examined subsequently by feeding sheep hay chopped to either 4 or 21 mm lengths. hducing the particle length of hay from 21 to 4 mm resulted in small increases (P &lt; 0.05) in the intake of dry matter (DM) [26.0 cf. 27.8 g per kg runen digesta-free liveweight (RFLW)] and organic matter (OM) (23.8 cf. 25.5 g per kg RFLW). Increases in intake were paralleled by increases (P &lt; 0.01) in loads of both rumen DM (29.7 cf. 33.9 g per kg RFLW, for 4 and 21 mm hay respectively) and OM (25.2 cf. 29.1 g per kg RFLW). The higher digesta load was associated with higher concentrations (P &lt; 0.05) of DM (133.6 cf. 122.5 g per kg total digesta) and OM (114.9 cf. 103.8 g per kg total digesta) in the rumen, but not with a difference in the measured packing density of particulate matter. The increase in the intake of 4 mm hay was totally attributable to the greater DM load of rumen digesta because the fractional outflow rate of particulate matter was lower for the 4 mm hay (0.55 cf. 0.63/day) and the apparent fractional rate of digestion was similar (0.42 cf. 0.43/day) in sheep fed the two lengths of forage.