Jatropha integerrima, Duranta erecta and Hibiscus rosa-sinensis as Potential Lead Absorbent from Polluted Air in Dense Traffic Area

Lead (Pb) is one of the contaminants found in polluted air, especially in the area with dense traffic. Herbaceous plants are potentially used to reduce the Pb content in the polluted air. This study was designed to evaluate the potential of several plants, such as Jatropha integerrima, Duranta erecta and Hibiscus rosa-sinensis, as Pb absorbents from polluted air based on Pb accumulation and chlorophyll levels. The lead content was measured using atomic absorption spectrophotometry (AAS), while the chlorophyll content was tested using spectrophotometers at wavelengths of 649 nm and 665 nm. Results showed that the three plant species had potential as Pb absorbents from the air. The highest lead content was found from J. integerrima at 1.293 mg/kg, followed by H. rosa-sinensis at 1.232 mg/kg and D. erecta at 0.840 mg/kg. On the other hand, the highest level of leaf chlorophyll content was H. rosa-sinensis at 16.116 mg/kg, followed by D. erecta L. at 12.594 mg/kg and J. integerrima Jacq. of 10.297 mg/kg. No correlation was found between the Pb level and chlorophyll content of the three plants. It can be concluded that the three herbaceous plants have potential as Pb absorbents in the polluted air.

Assessment and Monitoring of Carbon Monoxide (CO) Concentrations in High Traffic Areas (HTA) of Maiduguri Metropolitan of Borno State, Nigeria

The research investigated the carbon monoxide concentrations in heavy traffic areas of Maiduguri metropolitan between three weeks has been performed. Maiduguri City is located at latitudes 11 42N and 12 00 N and longitudes 12.54 and 13 14 E and has a land area of 543 km2 in the Northern-Eastern region of Nigeria. The high concentration of Carbon monoxide (CO) pollutants in high traffics area of Post office of Maiduguri city. The high traffic area (HTA) was selected for the research and the concentration of Carbon monoxide was monitored and measured, monitoring and measurement were planned daily between 8:00 a.m. to 8:00 p.m. for three weeks. The average result obtained was the highest point of 36 ppm and lowest point of 12 ppm in the three weeks, the highest point is above both WHO and FEPA points of 25 ppm and 30 ppm, respectively.

Measuring Average Luminance for Road Lighting from Outside the Carriageway with Imaging Sensor

The main quality condition in street lighting is luminance distribution. During the carrying out of the literature, average luminance is the most important parameter to check. The standard BS EN 13201-3 imposes that average luminance must be calculated for the observer placed in the center of each circulating lane. As a consequence, according to these standards, the measurements can be done only on streets without traffic. Stopping the traffic on all lanes is very difficult. This paper proposes a solution for measuring the average luminance from outside the carriageway. The research was performed by simulations/calculations and was validated by field measurements. Imaging sensors were used to measure average luminance, while DIALux EVO 9.1 was used for the simulations. For symmetrical, opposite, and staggered lighting arrangements, average luminance measurements were performed with a digital camera positioned outside of the traffic area, with the equipment placed at the edge of the carriageway, giving similar results with standard measurements, with almost no difference. For single sided lighting arrangements, the differences became unacceptable. In this case, the paper proposes a correction function to calculate the average luminance for the observer placed on the carriageway, based on measurements with a digital camera placed outside the traffic area.

Subdivision of Urban Traffic Area Based on the Combination of Static Zoning and Dynamic Zoning

In this paper, the traffic area of subzone division in urban road network is studied and a subzone division method based on the combination of static partition and dynamic partition is proposed. The static partition is carried out for the road network when the traffic flow is in a noncongested state, so as to provide the decision-making basis for the traffic green wave signal control strategy. At the same time, aiming at the road network when the traffic flow is congested, the dynamic partition is carried out on the basis of static partition to provide the decision-making basis for the traffic maximum flow signal control strategy. In view of the fact that it is difficult to determine the clustering center point during the initial division, this method proposes to determine the clustering center point according to the value of nodes of betweenness centrality. In order to solve the problem that it is difficult to collect traffic data, a method for estimating traffic flow density is proposed. In order to solve the problem of normalization of different probability distribution among various parameters, Mahalanobis distance is used as the fusion index of subzone division. Model verification shows that the method is feasible and effective.

Sources and Level of Rare Earth Element Contamination of Atmospheric Dust in Nigeria

Background. Rare earth element (REE) composition of atmospheric dust has recently been used to trace potential sources of dust pollution. Objective. The present study aimed to determine the sources of atmospheric pollution in the study area using REE patterns and determine their level of pollution. Methods. Twenty-five (25) atmospheric dust samples were collected in the study area, with five samples each from an industrial area, traffic area, dumpsite area, residential area and remote area in Ibadan, southwestern Nigeria. In addition, five (5) topsoil and two (2) rock samples (granite gneiss) were collected for comparison. Concentrations of REE were determined by inductively coupled plasma mass spectrometry (ICP-MS). Results. The ratio of lanthanum/cerium (La/Ce), especially in some locations in industrial area (1.5), traffic area (1.5) and to some extent dumpsite area (1.1) was higher than in soil (0.2), upper continental crust (0.5) and the minimum value of fluid catalytic crackers (1.0). Generally, the respective average values of the ratios of La/praseodymium (Pr), La/neodymium (Nd) and La/samarium (Sm) in industrial area (32.1, 7.8 and 52.6) and traffic area (14.9, 4.4 and 26.8) were higher than their respective averages in soil (4.4, 1.1 and 6.2), rock (5.7, 1.9 and 14.1), upper continental crust (4.4, 1.1 and 6.6) and the minimum value in fluid catalytic crackers (5.8, 3.7 and 37.0). Meanwhile, their corresponding value in the dumpsite area, residential area and remote area were lower or similar to the geological background levels. Discussion. The contamination factors of REEs in the atmospheric dust of the industrial area and traffic area were classified as heavily contaminated, especially with light lanthanoid elements in REE. The degree of contamination of REEs in the atmospheric dust of industrial area (30.9) and traffic area (18.8) fell within the considerable contamination category. The high values of the light lanthanoid ratio and the contamination indices were attributed to their emission from the fired-power plant and vehicular exhaust. Conclusions. Most of the composition of the atmospheric dust was sourced from the local geology of the study area as observed in the residential area and remote area, while the contamination in the industrial area and traffic area was attributed to human activities. Competing Interests. The authors declare no competing financial interests.

The Seasonality Impact of the BTEX Pollution on the Atmosphere of Arad City, Romania

Benzene, toluene, and total BTEX (benzene, toluene, ethylbenzene, and xylene) concentrations registered for one year (2016) have been determined every month for one high-density traffic area. The assessment was performed in Arad City, Romania, to evaluate these pollutants and their influence on the inhabitants’ health. The contaminants were sampled using a static sampling method and analyzed by gas chromatography coupled with mass spectrometry. Benzene was the most dominant among the BTEX compounds—the average concentrations ranged from 18.00 ± 1.32 µg m−3 in December to 2.47 ± 0.74 µg m−3 in August. The average toluene concentration over the year was 4.36 ± 2.42 µg m−3 (with a maximum of 9.60 ± 2.39 µg m−3 in November and a minimum of 1.04 ± 0.29 µg m−3 in May). The toluene/benzene ratio (T/B) was around 0.5, indicating substantial contributions from mobile sources (vehicles). The emission and accumulation of different aromatic compounds (especially benzene) could deteriorate the urban air quality. The lifetime cancer risk (LTCR) for benzene was found to be more than 10−5 in winter, including the inhabitants in the “probable cancer risk” category.

Auto-exhaust pollution effects on the leaf structure of Olea europea L.

Effects of auto-exhaust pollution on the leaf structure of Olea europea L. (Olive) were determined. Olive leaves were collected from three areas, such as, no low and heavy traffic areas with different traffic intensity. Anatomical layer thickness of leaves was studied in cross sections. Results showed that, the least values of layer thickness of leaves and total leaf thickness were obtained from high traffic area. Auto-exhaust pollution caused chlorosis and necrosis in morphological structure of olive leaves as well. The plant tolerated traffic-based pollution stress by decreasing anatomical layer thickness, however chlorosis occurred. Therefore, olive leaves can be used as a bio-indicator for traffic-based pollution because of their higher sensitivity to exhausts gases.