جستجوی مقالات مرتبط با کلیدواژه « pb » در نشریات گروه « پزشکی »

This study was conducted to investigate the effects of salicylic acid and rice husk ash on Pb and Cd concentration in pinto bean plants grown in soil that was contaminated with both diesel oil and heavy metals.

The treatments in this study included the application of rice husk ash to soil at concentrations of 0 %, 4 %, and 8 % (W/W) as well as the foliar application of salicylic acid to pinto bean plants grown in soil contaminated with diesel oil, Cd, and Pb at concentrations of 0 %, 4 % and 8 % (W/W). After a growth period of 90 days, the pinto bean plant was harvested and the concentration of Pb and Cd in the plants was measured using Atomic absorption spectroscopy. In addition, the extent of diesel oil bio-degradation in the soil was determined.

The results indicate a significant reduction in the concentration of Cd and Pb in pinto bean plants (by 11.7 and 15.4 %, respectively) due to the application of rice husk ash (8 % (W/W)) in the soil. Furthermore, the bio-degradation of diesel oil in the soil was found to be significantly enhanced, while the activity of plant enzymes APX and POX was observed to be decreased.

The interaction between rice husk ash and salicylic acid The reduction in Pb and Cd concentration was significantly influenced by, while the bio-degradation of diesel oil in the soil increased.

Soil poisoning with heavy metals is one of the most significant aspects of environmental research. In the soil treated with Thiobacillus, the effect of sulfur granular municipal solid waste (sulfur granular MSW), humic acid, and nano Fe-oxide on reducing Pb absorption by plants was investigated. Treatments consisted of applying sulfur granular MSW (0 and 30 t/ha), spraying humic acid (0 and 1.5 mmol/L), and using nano Fe-oxide (0 and 2% w/w) in the soil contaminated with Pb (0, 600, and 1200 mg/kg-soil). Plants were collected after 5 months, and the Pb content in the soil and plants was estimated by atomic absorption spectroscopy (AAS). The activity of ascorbate peroxidase (APX) and peroxidases (POX) enzymes were also determined. The use of 30 t/ha of sulfur granular MSW in the Pb-polluted soil reduced Pb concentration in the soil and plant by 13.4% and 15.1 %, respectively, while it increased Fe concentration by 15.2% in the plant. Using nano Fe-oxide (2% w/w) in the Pb-contaminated soil (600 and 1200 mg/kg soil) considerably enhanced Fe content in the plant. Pb absorption by plants was dramatically reduced by foliar application of humic acid. According to the findings of this study, the interaction effects of sulfur granular MSW, nano Fe-oxide, and humic acid significantly reduced the Pb absorption by plants. However, the impacts of soil physico-chemical characteristics and the kind of soil pollutant on plant Pb concentration cannot be ignored.

Remediation of heavy metals contaminated soils is a crucial issue. This study was conducted to evaluate the effect of nano Fe-oxide and multiwall carbon nanotubes (MWCNs) on diesel oil bio-degradation in the soil polluted with Pb and Cd  and enriched with vermicompost under ornamental sunflower cultivation.

Treatments were soil application of MWCNs at the rates of 0, 1, and 2 % (W/W); 0, 15, and 30 t/ha vermicompost; 0 and 0.5 % (W/W) nano Fe-oxide in soils polluted with Pb and Cd as well as 0, 4, and 8 % (W/W) diesel oil. After harvesting, the Pb and Cd concentrations of plant and soil were determined using AAS. Furthermore, the diesel oil bio-degradation in the soil was measured.

Using 1 and 2 % (W/W) MWCNs significantly increased the diesel oil bio-degradation by 15.3 and 17.4%, while the Pb concentration in soil decreased by 13.1 and 15.8%. In addition, the Cd concentration, decreased by 14.2 and 16.1%, respectively. The Pb and Cd concentrations in plant showed the similar trends. Using vermicompost significantly increased the diesel oil bio-degradation.

Using nano-Fe oxide and MWCNs significantly increased the biodegradation of diesel oil in soils polluted with Pb and Cd.

Petroleum hydrocarbon pollution in the soil is one of the important problems in environmental studies. Thus, this research was conducted to evaluate the effect of iron slag, zeolite, and Piriformospora indica fungus on mazut biodegradation in a heavy metal‑polluted soil that was amended with cow manure under canola cultivation.

Treatments included application of zeolite (0% and 2% [W/W]) and iron slag enriched cow manure (0, 15, and 30 t/ha) in a mazut‑polluted soil (0%, 4%, and 8% [W/W]) under canola cultivation in the presence of P. indica. After 70 days, plants were harvested and the mazut biodegradation in the soil was measured. In addition, the soil and plant Pb and Cd concentration was measured using atomic absorption spectroscopy.

Soil application of zeolite (2% [W/W]) in the mazut‑polluted soil (4% [W/W]) significantly increased the mazut biodegradation in the soil by 13.1%. In addition, plant inoculation with P. indica significantly increased the mazut biodegradation in the soil and decreased the plant Pb and Cd concentration. Soil application of cow manure at the rate of 15 and 30 t/ha has also increased the mazut biodegradation in the soil by 14.1% and 17.4%, respectively.

Using iron slag enriched cow manure and zeolite had additive effects of increasing the mazut biodegradation in the soil and decreasing the soil and plant heavy metal concentration. However, these changes depend on the plant physiology and soil physic‑chemical properties that should be considered in different studies.

The present study aimed to investigate the effects of salicylic acid (SA), humic acid (HA), and EDTA chelate on the increasing Pb concentration in a plant inoculated with plant growth-promoting rhizobacteria (PGPR). Treatments consisted of applying two levels of EDTA (0 (EDTA0) and 3 (EDTA3) mmol/kg soil) and soil application of HA (0 (HA0) and 200 (HA200) mg/kg soil). In addition, foliar application of SA at the rates of 0 (SA0) and 1.5 (SA1.5) mmol/lit was also sprayed on the inoculated plant with and without PGPR cultivated in the Pb-polluted soil. After 9 weeks, barley plants were harvested and plant Pb concentration was measured using atomic absorption spectroscopy (AAS). The soil Pb concentration and plant Pb biomass was also measured. The least significant difference (LSD) test was used to determine the differences between the means (P=0.05). The results indicated that application of HA or EDTA had significantly (P=0.05) increased the Pb phytoremediation efficiency, as, applying 3 mmol EDTA/kg soil increased the Pb phytoremediation efficiency by 14.1%. In addition, a significant increasing (P=0.05) in plant biomass and Pb phytoremediation efficiency was observed by 12.2 and 13.6%, respectively, in the inoculated plant cultivated in the soil that received the greatest rates of EDTA and HA together with the highest rate of SA foliar application. Plant growth regulators such as SA or humic acid can increase plant resistance to Pb toxicity and help to increase Pb phytoremediation efficiency that is important in environmental studies.

Today, finding suitable methods to decrease plant abiotic stress such as heavy metals or salinity is very necessary in arid and semi-arid regions. Thus, this research was conducted as a factorial experiment in the layout of a completely randomized block design to evaluate the role of Piriformospora indica fungus and multi-walled carbon nanotubes (MWCNTs) on decreasing plant abiotic stress in the soil treated with lead (Pb)-polluted sewage sludge. The treatment consisted of applying sewage sludge at the rates of 0, 15, and 30 t/ha, 3 levels of cadmium spiked in to the applied sewage sludge (0, 800 and 1600 mg Pb/kg), as well as 0%, 0.5%, and 1.5% (W/W) MWCNTs in the presence and absence of P. indica. The plant used in this experiment was barely. After 90 days of the experiment, the plant was harvested and its Pb concentration was measured using atomic absorption spectroscopy. Applying 0.5 and 1% (W/W) MWCNTs in the soil treated with 15 t/ha sewage sludge significantly decreased plant Pb concentration by 8.1% and 12.3%, respectively. In addition, the presence of P. indica had significant effects on decreasing plant Pb concentration since the lowest plant Pb concentration was observed in soil amended with 30 t/ha sewage sludge (800 mg Pb/kg) by receiving 1.5% (W/W) MWCNTs in the presence of P. indica. The results of this study showed that applying MWCNTs has significant effects on decreasing soil heavy metals or soil salinity that is a positive point in environmental studies.

Entrance of heavy metals into the respiratory system has adverse effects on human health. Accordingly, measuring metals concentration in places and times is necessary. This study was done to evaluate the non-carcinogenic risk of Pb, Cd, and As in air suspended particles of Baharestan city, in Isfahan, during 2016 - 2017. In order to evaluate the non-carcinogenic risk of heavy metals in air suspended particles (PM10), sampling was performed using a SKC pump with a low volume (1.5 L/min) and 37 mm membrane filter. Sampling was carried out on average every three days during 24-hours in May - June, July - August, October - November, and January - February; finally, the concentration of Pb, Cd, and As was determined using atomic absorption spectrometry (AAS) and hydride generation atomic absorption spectrometry (HGAAS), respectively. The acute and chronic non-carcinogenic risk of heavy metals sorption in the air was evaluated using the EPA method. The highest and lowest Pb concentration belonged to May - June and October - November, with the mean concentration of 0.25 and 0.14 mg/kg, respectively. For Cd it was 0.017 and 0.009 mg/kg, respectively. Similar results were found for the air suspended particles. The highest and lowest Cd non-carcinogenic risk was observed for permanent residents of Baharestan city and the non-dormitory students of this city with the mean of 3.1 × 10-5 and 1.4 × 10-5, respectively. The results of this study showed that the non-carcinogenic risk of heavy metals was lower than the standard level during the study years. However, heavy metal accumulation can threaten human health, which needs more consideration.

The present study aimed to measure the heavy metals existing in Isfahan’s dust at three stations during 2015-2017. This study was carried out in three stations located at north and northwest, west and southwest, and east and southeast parts of Isfahan. In each station, 12 sediment traps were placed and the concentrations of lead (Pb), cadmium (Cd) and zinc (Zn) in these sediment traps were determined using atomic absorption spectroscopy (AAS). The highest and the lowest concentrations of Pb in air dust were observed to be 490.1 and 70 mg/kg in western and eastern stations of Isfahan province, respectively. The highest and the lowest concentrations of Zn were 860.4 and 150 mg/kg in 2015, respectively. The highest Cd concentration (8.1 mg/kg) in air dust was found in the northern part of Isfahan province, while the lowest concentration of this metal (0.7 mg/kg) was observed in the eastern region of Isfahan. Similar results were obtained for the heavy metals enrichment factor with a maximum and minimum of 3.8 and 0.8 in 2015, respectively. The results of this study confirmed that the effect of human activities is significant in increasing the concentration of heavy metals such as Pb, Cd and Zn in dust. The assessment results for the enrichment factor of heavy metals revealed the contamination of dust by heavy metals. Accordingly, further attention is required to identify and control the pollutants sources such as heavy metals in dust in order to prevent the resulting pollution.

This study was conducted to determine the concentrations of Ag, Cd, Cr, Cu, Fe, Ni, Pb, and Zn in the commonly used cosmetic products such as eyeshadows, eyeliners, and skin whitening creams in markets of Sanandaj city, Iran in 2014. In this study, 60 samples comprising of three different types of eyeshadows, eyeliners, and skin whitening creams were purchased randomly from different cosmetic shops in Sanandaj city. The cosmetic product samples were digested using wet digestion method. Trace elements were assayed using an ICP-OES. According to the results, Ag and Fe were the trace elements with the lowest and highest concentration in the three brands, respectively. Moreover, the results indicated that eyeshadow contains the highest (except Ag and Cd) concentrations of trace elements. On the other hand, the levels of HQ for trace elements in the cosmetic products decreased in the following order: Zn > Cr > Cd > Fe > Cu > Ag > Ni > Pb. The trace element concentrations in the three brands of cosmetic products in our research were lower than the international standards and similar to those reported from researchers in different parts of Iran, but according to the accumulation and toxicity of these trace elements in the human body, they require periodic monitoring.

As more people live in cities and urban areas, evaluation of urban environmental quality is nowadays an unavoidable necessity. Urbanization gives off heavy metals into urban soils and threatens the human health. In this study, urban soil samples were acquired from different locations (Public parks, streets, and squares) from Borujerd, Iran. The levels of Cd and Pb in the soils, along with soil pH, electrical conductivity (EC), and particle size distribution (texture), were analyzed. Kriging method by Surfer software was employed to create the spatial distribution maps of Cd, Pb, and geoaccumulation index (Igeo). The average Cd and Pb concentrations in the surface soil samples were 2.50±1.14, and 50.37±34.77 mg/kg dry weight, respectively. The highest mean concentration of Cd was found in street soils and as for Pb in square soils. The interpolation maps illustrated the same behavior for Cd and Pb with elevated concentrations located in the southeast. The mean values of geoaccumulation index (Igeo) showed that soils are moderately/strongly contaminated with Cd and moderately contaminated with Pb. In this study, traffic emission, textile industries and probably released untreated municipal wastewater into the soil are anthropogenic sources of Pb and Cd.

To assess the salivary composition of proteins and minerals in smokers compared with non-smokers. In this study we compared the total protein and Ca, Na, K, Mg, Pb of whole saliva in two groups of men (28 smokers and 31nonsmokers) aged between 29-41years. Fifty-nine participants were evaluated. The mean age was 33.14±5.32 years among smokers and 32.15±5.12 years among non-smokers (P>0.05). The mean concentration of total protein, Ca, Pb,and Zn of whole saliva in smokers was lower than that in non-smokers, but the difference was not statistically significant (P>0.05). The mean concentration of Na, K, Mg in whole saliva was not significantly different between smokers and non-smokers (P>0.05). We specified that smoking reduced the value of total protein, Ca and Pb of saliva, however it did not havean impact on Na, K, and Mg of saliva.

 The concentration of Cd, Cr, Al and Pb present in inhalable air and deposited dust in a metal-mechanical parts manufacturing plant in Puebla, México were determined in order to assess the occupational exposure of workers in this plant. 

 Fourteen air samples, six from the metal welding (MW) and eight from the metal forming (MF) areas, as well as metal dust accumulated on the floor of an auto part manufacturing plant, were collected. Sampling and analysis followed the National Institute for Occupational Safety and Health (NIOSH) recommended methods for metals in inhalable air. 

 The average concentration of Al and Cd determined in a volume of inhalable air were adequate under NIOSH maximal exposure concentration limits in both sampled sites. Average concentrations of 0.001 (MF sampling site) and 0.105 μg/L (MW sampling site) for Al; 0.003 (MF) and 0.0005 (MW) μg/L for Cd, with respect to the NIOHS limits, 10 and 0.005 μg/L, for Al and Cd, respectively. However, Cr and Pb concentrations exceeded or were close to the limits recommended by NIOHS in both places (0.5 and 0.05 μg/L for Cr and Pb, respectively). Average concentrations of 0.345 (MF) and 0.77 (MW) μg/L for Cr and 0.153 (MF) and 0.649 (MW) μg/L for Pb, were determined. Levels of metal content (Cd, Cr and Pb) in powder samples collected in both sampling sites were also higher than the suggested limits. 

 The average concentration of Cr and Pb exceeded the limits recommended by the Occupational Safety and Health Administration and NIOSH for inhalable air in the workplace. Workers may be on risk of heavy metal occupational exposure. It is endorsed to implement safety measurements to avoid the breathing of contaminated air and also industrial level systems for dust and aerosol particle filtering or precipitation, altogether with stricter policies to regulate heavy metal exposure at these industries.