scholarly journals Levels of Heavy Metals in some Commercially available Rice on the Liberian Market

Author(s):  
G. L. Gomah ◽  
R.B. Voegborlo ◽  
R. S. Ngumbu

Human activities such as agriculture, mining, urbanization and waste disposal can lead to heavy metals contamination of food crops, including rice meant for human consumption. In an effort to ensure quality and safe food consumption, this study determined the levels of toxic heavy metals, Arsenic (As), Cadmium (Cd), Chromium (Cr), Lead (Pb), Mercury (Hg) and Nickel (Ni) in rice brands widely consumed in Liberia. Hg was determined by AAS technique using a Lumex RA-915M portable Zeeman Automatic Mercury Analyzer. As, Cd, Cr, Pb and Ni were determined by ICP-MS technique using an Agilent 7900 ICP-MS. The levels of As, Cd, Cr, Pb, Hg and Ni concentrations ranged from 1.1 to 18.1, 4.8 to 117.9, 50 to 424.5, 1.1 to 37.1, 1.1 to 9.4 and 15.1 to 655.2 µg/kg respectively. The study revealed no significant statistical variability in the metal concentrations between the locally cultivated and imported rice, except for As (P = 0.002). The levels of As, Cd, Pb and Hg in all brands were below the World Health Organization/Food and Agricultural Organization guideline values. Cr and Ni levels were also below the European Commission Guidelines for all rice brands analyzed. The results imply that although the rice brands analyzed contain low heavy metal concentrations, the levels are unlikely to cause adverse health effects to the consuming populace.

1987 ◽  
Vol 26 ◽  
pp. 51-58
Author(s):  
Horas Hutagalung ◽  
Suwirma Syamsu

Determination of  heavy  metal  content  (Hg, Pb, Cd, Cu, Cr, Zn) in some seafoods collected from  Muara  Angke  Fish  Auction  Place  were carried out during February to July 1979. The results showed  that Zn  content  in seafoods a nalyzed  was always much higher than the other heavy metals. The concentration levels of  the  six  heavy  metals observed were low. It is almost of the same level as the metal concentration of  other  seafoods  observed  in various parts of the world oceans, but still lower  than the maximum standard set  for human  consumption  as  established  by   Tasmania, Australia and  World Health Organization. The  mean  per capita  consumption of  fish  in Jakarta is only  about 165 g  per week, while  the  Provisional Tolerated Weekly Intake for Hg, set by WHO/FAO at 300 ug level, would be attained by consuming 1500 g Rastrelliger sp., or 698 gPenaeus setiferus, or 545 g Sepia sp., and or 1250 g Pecten sp.  Therefore,  at   present the  level of metal content in fishes sold at TPI  Muara  Angke  can be  considered  as  not  dangerous  to human health as long as these quantities are not surpassed.


2017 ◽  
Vol 7 (14) ◽  
pp. 48-61 ◽  
Author(s):  
Olatunde Sunday Eludoyin ◽  
Onisoya Margaret Ogbe

Background. Consumption of plants such as Carica papaya grown around automobile workshops is common in big cities in Nigeria. However, little is known about the heavy metals contamination of these consumables due to the influence of automobile emissions during maintenance activities. Objectives. This study aimed to assess heavy metal concentrations in C. papaya and supporting soils around automobile workshops in Port Harcourt Metropolis, Rivers State, Nigeria. Methods. Seven automobile workshops were used for the present study. First, 20 m × 20 m quadrats were laid out for soil and C. papaya tissue sampling. One composite soil sample was collected from the topsoil (0–15 cm depth) around each of the automobile workshops. Three C. papaya stands at least 30 cm apart around each workshop were used for the study and from these stands, tissues (root, stem, leaf, fruit) of C. papaya were collected. Standard laboratory techniques were used to determine the pH, electrical conductivity (EC) and heavy metals (lead (Pb), mercury (Hg), cadmium (Cd), copper (Cu), and zinc (Zn)) in the soil samples and C. papaya tissues. Pairwise t-test was used to determine significant differences (p<0.05) in the heavy metal concentrations in soil and C. papaya tissues between the sample and control sites, while correlation statistics were used to determine the relationship of heavy metal concentrations between soil and C. papaya tissues. Results. C. papaya tissues and supporting soil had significantly higher levels of pH, EC and heavy metals in the sampled plots than the control plot. The heavy metal concentrations in C. papaya and soil occurred in the decreasing order of Pb>Cu>Hg>Zn>Cd. The fruit of C. papaya had the highest mean concentrations of Pb (51.4±14.1 mg/kg) and Zn (26.4±1.9 mg/kg), while the leaf had the highest mean concentration of Hg (32.0±2.3 mg/kg). The pH, Cu and Zn in the supporting soil were significantly correlated with the levels in the C. papaya tissues. Conclusion. Bio-accumulation of heavy metals by C. papaya is evident around automobile workshops, and Pb, Hg, Cd concentrations were found to be above the permissible limits for human consumption according to World Health Organization (WHO) standards. Consumption of food materials grown around automobile workshops could pose health risks. Competing interests. The authors declare no competing financial interests.


1987 ◽  
Vol 26 (1) ◽  
pp. 51 ◽  
Author(s):  
Horas Hutagalung ◽  
Suwirma Syamsu

Determination of  heavy  metal  content  (Hg, Pb, Cd, Cu, Cr, Zn) in some seafoods collected from  Muara  Angke  Fish  Auction  Place  were carried out during February to July 1979. The results showed  that Zn  content  in seafoods a nalyzed  was always much higher than the other heavy metals. The concentration levels of  the  six  heavy  metals observed were low. It is almost of the same level as the metal concentration of  other  seafoods  observed  in various parts of the world oceans, but still lower  than the maximum standard set  for human  consumption  as  established  by   Tasmania, Australia and  World Health Organization. The  mean  per capita  consumption of  fish  in Jakarta is only  about 165 g  per week, while  the  Provisional Tolerated Weekly Intake for Hg, set by WHO/FAO at 300 ug level, would be attained by consuming 1500 g Rastrelliger sp., or 698 gPenaeus setiferus, or 545 g Sepia sp., and or 1250 g Pecten sp.  Therefore,  at   present the  level of metal content in fishes sold at TPI  Muara  Angke  can be  considered  as  not  dangerous  to human health as long as these quantities are not surpassed.


Author(s):  
Elif Çağrı Taş ◽  
Uğur Sunlu

This study was carried out to determine the concentrations of some heavy metals (Cd, Cu, Pb, Zn, Cr and Fe) in Solen marginatus (Pulteney, 1799) and sediments in the middle region of Izmir Bay. Metal concentrations in S. marginatus vary in the one-year period between summer 2005 and summer 2006. The order of accumulation of metal concentrates in soft tissue of razor clam was determined as Cd < Pb < Cr< Cu < Zn < Fe. Metal accumulations in the soft tissue of S. marginatus were compared with Provisional Tolerable Weakly Intakes (PTWI) and Provisional Tolerable Daily Intakes (PTDI) for human consumption. The results show that the maximum concentrations of metals were markedly below the limits of the FAO (Food and Agriculture Organization), WHO (World Health Organization) and TFC (Turkish Food Codex) for human consumption. The order of the metal concentrations detected in the sediment samples was Cd < Pb < Cu< Cr < Zn < Fe. In this study, the maximum heavy metal values determined in the sediment are below the criteria values of the stated for international sediment quality guidelines in the NOAA (The National Oceanic and Atmospheric Administration), OMEE (The Ministry of Environment and Energy of Ontario), ANZECC (The Australia and New Zealand Environmental on Conservation Council), CCME (The Canadian Council of Ministers of Environment). There was a statistically significant but weak correlation between concentrations of Cu and Cr in sediment and S. marginatus. The significant correlations have shown that Solen species can be used as a bioindicator species, such as mussels due to their ability to accumulate heavy metals.


2018 ◽  
Vol 7 (4.35) ◽  
pp. 219
Author(s):  
Haron S.H ◽  
Ismail S ◽  
Sidek L.M

The existence of heavy metals residues in water, soil and air poses a serious risk to all living organisms. Heavy metals, such as Cd, Pb, Cr, Ni, and Hg, are major sources of environmental pollution, especially in areas with high anthropogenic and agriculture activities. The objective of this study is to determine the status of heavy metal concentrations of Cd, Cr, Ni, Pb, Zn, Cu, and Fe in the water bodies of Bertam River, which passes through agricultural areas. The water samples were collected randomly in three replicates from 10 sampling points along the Bertam River. The heavy metals in the water were extracted by using filter paper with a pore size of 0.45 mm. The extracted water sample was preserved by adding nitric acid (pH <2). Sample concentrations were then tested for metal concentrations using inductively coupled plasma mass spectrometry. In this study, the highest mean concentration was Fe (96.04 ± 90.43 ppb), followed by Zn (5.68 ± 0.2.34 ppb), Cu (5.13 ± 2.98 ppb), Cr (1.53 ± 0.19 ppb), Ni (0.85 ± 0.22 ppb), Pb (0.85 ± 1.61 ppb), and Cd (0.027 ± 0.02 ppb), where Fe> Zn> Cu> Pb> Cr> Ni> Cd. However, the concentrations of selected heavy metals in the water samples were below the standards recommended by the World Health Organization.


2016 ◽  
Vol 17 (3) ◽  
pp. 780-791 ◽  
Author(s):  
Célestin Defo ◽  
Yerima Bernard Palmer Kfuban ◽  
Ravinder Kaur ◽  
Nestor Bemmo

The present study was aimed at bridging the gaps in the knowledge concerning heavy metals (Pb, Cd, Cr, Ni, Zn, Cu, Mn and Fe) concentrations in the groundwaters of the Ntem watershed in Yaoundé. Representative groundwater samples (25 numbers) were collected from five hand-dug wells, and their metal concentrations were assessed as per standard procedures, and deterministic interpolation techniques were used to perform the spatial distribution of heavy metal concentration maps. The ranges of concentrations of these metals in groundwaters were: Pb (0.11–0.34 mg/L &gt; 0.025 mg/L); Cd (0.00–0.08 mg/L &gt; 0.005 mg/L); Cr (0.12–1.33 mg/L &gt; 0.05 mg/L) and Ni (0.11–0.46 mg/L &gt; 0.05 mg/L). Besides, the average metal concentrations in the groundwaters of the sampling sites were in general higher than the prescribed World Health Organization (WHO) norms. The risk assessment indicated that the population concerned are considered unsafe, and are therefore exposed to non-carcinogenic and carcinogenic effects on health. The occurrence of more than permissible levels of heavy metals in the representative groundwaters and their spatial distribution indicate that there is a potential threat from these contaminants to the public health in the Ntem watershed.


2020 ◽  
Vol 12 (2) ◽  
pp. 70-77
Author(s):  
Truong Xuan VUONG

Plants might contain heavy metals from the surrounding polluted environment. Medicinal herb and plants, commonly used in Vietnam, may pose a risk to public health when polluted with heavy metals such as Pb, Cd and As. This study aims to investigate the content of Pb, Cd, and As in five selected herb plants (Phyllanthus urinaria L., Plantago asiatica L., Eleusine indica L., Wedelia chinensis (Osbeck) Merr, and Artemisia vulgaris L.). The samples were collected from natural sites in some provinces in northern Vietnam. The concentrations of Pb, Cd, and As were determined by the Inductively coupled plasma mass spectrometry (ICP-MS) method. The content of Pb, Cd and As was 0.247 ÷ 32.080 mg kg-1, 0.000 ÷ 1.099 mg kg-1, 0.000 ÷ 2.261 mg kg-1, respectively. A total of 50 out of the 58 investigated samples had concentrations of Pb, Cd, As lower than the permissible values of the World Health Organization (WHO). The remaining samples had contents of Pb or Cd or As significantly higher than the permissible limit defined by WHO. Thực vật có thể bị ô nhiễm do hấp thụ kim loại nặng từ môi trường ô nhiễm xung quanh. Các loại cây thảo dược được sử dụng phổ biến làm thuốc chữa bệnh ở Việt Nam. Chúng có thể gây nguy hiểm cho sức khỏe cộng đồng khi bị ô nhiễm kim loại nặng (Pb, Cd...vv.). Nghiên cứu này nhằm điều tra hàm lượng Pb, Cd và As trong năm loại cây thảo dược (cây Diệp Hạ Châu, cây Mã Đề, cây Cỏ Mần Trầu, cây Sài Đất và cây Ngải Cứu). Các mẫu cây này được lấy từ các địa điểm mọc tự nhiên ở một số tỉnh khác nhau thuộc khu vực miền bắc Việt Nam. Hàm lượng của Pb, Cd, và As được xác định bằng phương pháp ICP-MS. Hàm lượng Pb, Cd và As trong các mẫu phân tích lần lượt nằm trong khoảng là 0.247 ÷ 32.080 mg. Kg-1, 0.000 ÷ 1.099 mg. Kg-1, 0.000 ÷ 2.261 mg. Kg-1. 50 trên 58 mẫu phân tích có hàm lượng Pb, Cd, As thấp hơn giới hạn cho phép do tổ chức y tế thế giới (WHO) quy định. Có 8 trên 58 mẫu cây phân tích có hàm lượng Pb hoặc, Cd hoặc As cao hơn tiêu chuẩn giới hạn của WHO.


2021 ◽  
pp. 46-51
Author(s):  
Wilfred–Ekprikpo P. C.

This study investigated the heavy metal concentrations in different organs such as gills, muscles, liver and gatro-intestinal tract (GIT) of two species of Goby: Porogobius schelegelii and Bathygobius soporator from Buguma Creek, Rivers State, Nigeria. The fish samples were collected from the creek and were preserved in ice chest box and transported to the laboratory for analysis. Samples were digested by using standard laboratory methods. The concentrations of metals were analyzed using a Varian AA240 Fast Sequential Flame Atomic Absorption Spectrophotometer (AAS). The Results obtained indicated that heavy metals such as Chromium (Cr), Lead (Pb), Zinc (Zn), Cadmium (Cd), and Nickel (Ni) were significantly higher (p<0.05) in the liver of the two species than in the muscle, gills and the GIT. Comparatively, the concentrations of these metals were higher in the specie B.soporator than P. schelegelii in all the organs of the fishes under consideration. The heavy metal concentrations recorded in this study were above the limits recommended by Food and Agricultural Organization/ World Health Organization. The high concentration of heavy metals above permissible level suggests the need for caution during the consumption of these species from Buguma Creek due to health implications associated with heavy metals.


Author(s):  
N. K. Ochiba ◽  
D. A. Abong'o ◽  
J.O. Onyatta

The study was carried out to evaluate the levels of heavy metals in groundwater samples from ten selected boreholes in Ongata Rongai town, Kajiado County. The selected heavy metals analyzed were: Zn, Pb, Hg, Mn, Cd and Cr in the dry and wet seasons. The effect of the proximity of septic tanks distance to borehole was also determined. The statistical analyses of the data using a 2-way ANOVA showed 95% confidence level (p<0.05) interdependence of the distance from the boreholes and contaminant levels. The study showed that heavy metals were below the maximum recommended level and the guideline values of World Health Organization and Kenya Bureau of Standards. The analyses of the selected heavy metals, by Flame Atomic Absorption Spectroscopy, revealed that the detected levels of Mn (0.03±0.01 - 0.26±0.01 mgl-1) were higher than those recommended by WHO and KEBS of 0.01 mgl-1, while Zn (0.11±0.02 - 0.73±0.01 mgl-1) are within acceptable levels of WHO (3.0 mgl-1) and KEBS (5.0 mgl-1). There was no strong correlation between the distance of borehole from septic tanks and heavy metal levels in water samples. The low detected values should not be overlooked as the heavy metals are capable of bio-accumulating in body tissues.


CORD ◽  
2010 ◽  
Vol 26 (1) ◽  
pp. 7
Author(s):  
Warsakoon, W.M.M.P.D.K.

Coconut is one of the major plantation crops which plays a pivotal role in the economy of Sri Lanka. The objective of this study is to investigate the presence of heavy metals in fresh coconut kernel and in some coconut products in Sri Lanka. Levels of lead (Pb), Chromium (Cr), Aluminum (Al), Ferrous (Fe), Copper (Cu), Manganese (Mn), Cadmium (Cd), Zinc (Zn), and Arsenic (As) were determined in samples of fresh coconut kernel, coconut milk, coconut milk powder, and coconut cream using the Atomic Absorption Spectrometer (AAS) method. Fresh coconut kernel and coconut products were found to contain Fe, Zn, Cu and Mn. Fresh coconut kernels showed the highest content of these metals. Coconut cream and coconut milk samples demonstrated the lowest levels of these metals. Potentially toxic heavy metals such as Pb, Cd, As, and Al were not detected in the tested samples. The occurrence of the heavy metals in all the coconut products tested was below the permissible levels suggested by the USDA, World Health Organization, and the Quality Standards of CODEX Vol. 1 Section 6, 1991.


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