Non-carcinogenic Risk For Children Research Articles

Risk assessment of heavy metals in soil based on the geographic information system-Kriging technique in Anka, Nigeria

Soil contaminated with heavy metals from artisanal gold mining in Anka Local Government Area in Northwestern Nigeria was investigated to evaluate the human health risk as a result of heavy metals. Measured concentration of heavy metals and exposure parameters were used to estimate human carcinogenic and non-carcinogenic risk. GIS-based Kriging method was utilized to create a prediction maps of human health risks and probability maps of heavy metals concentrations exceeding their threshold limits. Hazard index calculation showed that 21 out of 23 locations are posing non-cancer risk for children. Adults and children are at high cancer risk in all locations as the total cancer risk exceeded 1×10−6 (the lower limit CTR value). Kriging model showed that only a very small area in Anka has a hazard index of less than unity and cumulative target risk of less than 1×10−4, indicating a significant carcinogenic and non-carcinogenic risks for children. The probability of heavy metals to exceed their threshold concentrations around the study area was also found to be high. Keywords: Carcinogenic, Heavy metals, Human risk assessment, Kriging, Non-carcinogenic

Pollution characteristics and health risk assessment of heavy metals in the vegetable bases of northwest China

The objective of this study was to investigate heavy metal contamination in four major vegetable bases and determine the health risks of residents in the vicinity of the highly urbanized city Urumqi in Xinjiang, China. In this paper, we determined the contents of six heavy metals (i.e., As, Zn, Cd, Cr, Hg, and Pb) in surface soil and groundwater to evaluate the levels of heavy metal pollution and human health risks using the pollution index (PI), the Nemerow integrated pollution index (NIPI), the ecological risk factor (Eir), risk index (RI) and the health risk assessment model. The results showed that (1) The PI, NIPI, the ecological risk factor and risk index indicated that Cd and Hg were the primary pollutants in Sishihu village. These indices suggested moderate to slightly heavy potential ecological risks. In Anningqu town, Hg and Cd led to high levels of pollution and posed slightly heavy potential ecological risks. In Qinggedahu village, it was concluded that the metals Zn, Cr, Cd, Hg, and Pb caused moderate to heavy pollution. In Liushihu village, the pollution trends in the area were low. The results of the pollution level of the irrigation well water (i.e., groundwater) indicated that the well water was considerably safer than the soil, but Cr posed a slight pollution risk. (2) The non-carcinogenic risks for adults based on the HI values of these four vegetable bases were <1. However, when considering the non-carcinogenic risks for children, the HI values were larger than 1 in all areas, indicating the local children have a higher potential non-carcinogenic risk. In addition, CR (Carcinogenic risk) from dermal contact with the vegetables bases did not pose a high risk for residents. However, for adults, the carcinogenic risk posed by Arsenic (As) through trough inhalation was the primary pathway of exposure in three of the vegetable bases, generally in the order of Qinggedahu village > Sishihu village > Anningqu town. For children, the carcinogenic risks posed by As through trough inhalation and ingestion were the main exposure pathways. From the TCR results, it can be seen that in Sishihu village, Anningqu town, and Qinggedahu village, the TCR values for adults and children were >1 × 10−4 (unitless), and this degree of carcinogenic risk is unacceptable. (3) The identification of risk sources determined the main pollution sources affecting the vegetable bases were human activities and natural sources. Anthropogenic activities were most often related to traffic pollution sources and agricultural pollution sources, such as the irrational use of pesticides and fertilizers and stock farming. The results are important for designing remediation scenarios to control the spread of contamination as well as for serving as a reference point for soil environmental protection efforts in this region.

Analysis of drinking water quality from the standpoint of health risks

The paper presents a hygienic quality assessment of water from sources in the Irkutsk Region (Russia) used for public drinking water supply. The aim of the study is to assess health risks to the population of Bratsk and the Bratsk District, which is associated with the exposure to chemicals coming with drinking water from the public water supply system. Risk of occurrence and development of non-carcinogenic effects is assessed for separate age groups using a special method. Based on the risk assessment methodology, non-carcinogenic risks for children and adults are described in quantitative terms. The total health risk of the test groups associated with the oral intake of chemicals with drinking water is estimated as negligible and, therefore, does not need to be reduced through additional measures. Lead and fluoride contents in drinking water are the major contributors to the risk level (59.5–68.4%). There is a risk of developing blood disorders and cardiovascular diseases in children of Bratsk (HI = 1.19), as well as bone tissue and teeth disorders in children of Bikey village, Bratsk District (HI = 1.10).

Analysis of drinking water quality from the standpoint of health risks

The paper presents a hygienic quality assessment of water from sources in the Irkutsk Region (Russia) used for public drinking water supply. The aim of the study is to assess health risks to the population of Bratsk and the Bratsk District, which is associated with the exposure to chemicals coming with drinking water from the public water supply system. Risk of occurrence and development of non-carcinogenic effects is assessed for separate age groups using a special method. Based on the risk assessment methodology, non-carcinogenic risks for children and adults are described in quantitative terms. The total health risk of the test groups associated with the oral intake of chemicals with drinking water is estimated as negligible and, therefore, does not need to be reduced through additional measures. Lead and fluoride contents in drinking water are the major contributors to the risk level (59.5–68.4%). There is a risk of developing blood disorders and cardiovascular diseases in children of Bratsk (HI = 1.19), as well as bone tissue and teeth disorders in children of Bikey village, Bratsk District (HI = 1.10).

Assessment of the potential health risks of heavy metals in soils in a coastal industrial region of the Yangtze River Delta.

Soil heavy metal contamination is a serious environmental problem. Human beings may be directly exposed to heavy metals in soils through the inhalation of soil particles, dermal contact, and oral ingestion, which can seriously threaten health. This study assesses the health risks associated with heavy metals in soils by determining the concentrations of eight heavy metals (Cr, Pb, Cd, Hg, As, Cu, Zn, and Ni) based on 2051 surface-soil samples collected from the southern Yangtze River Delta of China. The mean concentrations were higher than the corresponding background values in Zhejiang Province and China as a whole, indicating an accumulation of heavy metals. The health risk assessment suggests that the non-carcinogenic and carcinogenic risks in the study area were not significant. The non-carcinogenic risk for children was the highest, followed by those for adults and seniors; the non-carcinogenic risk for the entire population was less than 1.0, the predetermined threshold. Carcinogenic risk for adults was the highest, followed by those for seniors and children; a few sample points had a value larger than the threshold of 1.0E-04. Arsenic represented the greatest contribution to non-carcinogenic and carcinogenic risk. Meanwhile, ingestion of heavy metals in soil was the main exposure pathway for carcinogenic risk, followed by inhalation and dermal exposure. The spatial method of Getis-Ord was used to identify hot spots of health risk. Hot spots with high hazard index (HI) and total carcinogenic risk (TCR) for children, adults, and seniors were mainly distributed in core urban areas, such as Jiangbei, Haishu, Yinzhou, Jiangdong, and the urban areas of some other counties, which coincided with industrial, mining, and urban areas of the study area and were strongly influenced by anthropogenic activities. These results provide a basis for heavy metal control in soil, source identification, and environment management in the Yangtze River Delta and other rapidly developing industrial regions in China.

Heavy metals pollution levels and children health risk assessment of Yerevan kindergartens soils

Children, the most vulnerable urban population group, are exceptionally sensitive to polluted environments, particularly urban soils, which can lead to adverse health effects upon exposure. In this study, the total concentrations of Ag, As, Ba, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Ti, V, and Zn were determined in 111 topsoil samples collected from kindergartens in Yerevan. The objectives of this study were to evaluate heavy metal pollution levels of kindergarten's soils in Yerevan, compare with national legal and international requirements on heavy metal contents in kindergarten soil, and assess related child health risk. Multivariate geostatistical analyses suggested that the concentrations of Ag, As, Ba, Cd, Cu, Hg, Mo, Pb, and Zn observed in the kindergarten's topsoil may have originated from anthropogenic sources, while Co, Cr, Fe, Mn, Ni, Ti, and V mostly come from natural sources. According to the Summary pollution index (Zc), 102 kindergartens belong to the low pollution level, 7 to the moderate and only 2 to the high level of pollution. Summary concentration index (SCI) showed that 109 kindergartens were in the allowable level, while 2 featured in the low level of pollution. The health risk assessment showed that in all kindergartens except for seven, non-carcinogenic risk for children was detected (HI>1), while carcinogenic risk from arsenic belongs to the very low (allowable) level. Cr and multi-element carcinogenic risk (RI) exceeded the safety level (1.0E- 06) in all kindergartens and showed that the potential of developing cancer, albeit small, does exist. Therefore, city's kindergartens require necessary remedial actions to eliminate or reduce soil pollution and heavy metal-induced health risks.

Potential health risk assessment for soil heavy metal contamination in the central zone of Belgrade (Serbia)

An investigation of the soil quality in the centre of Belgrade was per- formed to define how seriously the soil is polluted. On the basis of the heavy metal content (Zn, Cd, Pb, Co, Ni, Cu, Cr and Mn), the potential health risk assessment calculated for a lifetime of exposure (ingestion and inhalation), based on the USEPA model, was determined as the cumulative carcinogenic and non-carcinogenic risk for children and adults. The study proved that soil contamination in Belgrade is not insignificant; risk assessment indicated that the carcinogenic risk is completely insignificant but the cumulative non-carcinogenic risk tends to became significant, mainly for children, since it approaches unacceptable values. There is no particularly dangerous single heavy metal, but their cumulative effect, expressed as Child Soil Ingestion Hazardous Index, is for concern.