جستجوی مقالات مرتبط با کلیدواژه "ضریب همبستگی پیرسون" در نشریات گروه "پزشکی"

Today, soil and water pollution with heavy metals is one of the major challenges around the world. The aim of this study is to investigate the contamination of soils around a lead and zinc mine.

In the summer of 2019, 100 soil samples were taken from the mine vicinity and the characteristics of texture, acidity, salinity, calcium carbonate, organic matter and heavy metals chromium, cobalt, zinc, lead and cadmium were measured. Pollution indices including pollution factor (PI), enrichment coefficient (EF), geoaccumulation (Igeo), toxicity probability (MERMQ), contamination load (PLI), background enrichment (PIN), pollution security (CSI) and Nemerow index (PINemerow) ) Were calculated. Correlation between soil variables and determination of metal origin were determined using Pearson correlation and principal component analysis (PCA) analysis.

The average concentrations of chromium, cobalt, zinc, lead and cadmium were obtained as 92, 21.33, 453.98, 351.24 and 4.28 mg/kg, respectively. The metals pollution evaluated based on PI, EF and Igeo indices were moderate for chromium and cobalt, considerable for zinc and significant for lead and cadmium. The results of MERMQ, PLI, PIN, CSI and PINemerow indices showed high soil contamination with heavy metals. According to the PCA test, the elements lead, zinc and cadmium are in a group with high correlation with each other that are of anthropogenic origin. Chromium and cobalt with a correlation of 88% also showed the same geological origin.

mining activities should be done with more caution and measures should be taken to reduce pollution.

 Landfills as municipal solid waste are considered as the source of pollution. The present study aimed to assess the ecological risk of heavy metals in Tehran landfill soil and the adjacent residential area.

 Having consulted with the specialists and considered the waste processing facilities, 12 sampling points were selected and sampled in four seasons. Soil samples were digested using HNO3: HClO4: HCl: HF. The levels of metals were measured using ICP-OES which further applied for the calculation of ecological risk. Kolmogorov-Smirnov, Kruskal-Wallis, and Pearson correlation coefficient analyses were run to determine the significant differences between metals concentrations in various seasons and sampling points. 

 Metal concentration showed to follow theorder: Al > Fe > Mn > Zn > Cr > Pb > Cu >Ni > Co > As > Cd. Kruskal-Wallis results and pairwise comparison showed a statistically significant difference between metal concentrations across sampling points and seasons, especially in rainy seasons. Pearson correlation coefficient displayed a strong relationship between the mean concentrations of Cu - Pb, Cu - Zn, and Pb - Zn with obtained values of 0.932, 0.874, and 0.883, respectively. Cu exhibited the highest contamination factor at the compost and fermentation sites (13.2 and 9.89, respectively). The geo-accumulation index proved the anthropogenic sources of pollution. The potential ecological risk index (ERI) for the sampling sites ranged from 67.3 to 154, with the order of Cd > Cu > Pb > Ni > As > Cr > Zn > Co > Mn. 

 Due to the obtained moderate to severe ecological risk and exceeded background concentrations of heavy metals, it can be concluded that metal changes and soil pollution are both affected by landfill activities.

In recent years,cases of animal bites have increased in Iran. In addition,stray animals killing had upward trend,accordingly. The incidence rate of animal bites in Fereydunshahr is higher than the national average (499 vs. 188 per 100,000),it has great importance in this regard. Therefore killing of stray animals has constantly been the agenda of the relevant organs with a high cost,but does this program reduces the rates of animal bite? This study evaluated effectiveness of stray animals' Killing on animal bites incidence in Fereydunshahr (Isfahan,IRAN) in the last 18 years (2000-17).Materials, In this routine data base study,we followed 2339 cases of animal bites (using CENSUS method) that had been diagnosed,received Anti-Rabies vaccine during the studied period,as well as 2642 cases of animal waste. The data used in this study were collected from the township health center reports. Statistical computing was performed using SPSS software (ver. 19) at an error level of 5%. Pearson's Skewness coefficient showed that both the number of animal bites,also,killed animals have normal distribution. Given the existence of parametric conditions,normal distribution,variables independence,and the interval scale of both variables,Pearson Correlation coefficient test is used to investigate the relationship. Pearson correlation analysis did not show a significant correlation between stray animals' killing with animal bites incidence (P,0.74,ɤ,-0.023). Due to 84% of animal bite cases occurred by domestic dogs in the last 18 years,killing of stray animals not only had effect on reducing the incidence of animal bite cases,but also it increases the costs,immoral methods of animal killings. The plans such as training of dog-owners (to keep in fetters of the dogs),training of the population,especially schoolchildren,can be effective in domestic dog bites reduction.