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Investigation of Heavy Metal Levels in Drinking-and Well- Water Samples

Using ICP-MS Method

Leila Mehdizadehtapeh1*, İsmai̇l Hakki Teki̇ner2, Haydar Ozpinar3

1

Food Safety and Nutrition Department, Istanbul Aydin University, Turkey

2

Gastronomy Department, Istanbul Gelişi̇m University, Turkey

3

Food Safety and Nutrition Department, Istanbul Aydin University, Turkey

*Corresponding author ([email protected])

Abstract Article information:

Received 15 May 2017 Accepted 03 June 2017 Available online 5 June 2017

Keywords: drinking water

heavy metal human health Turkey well water

© 2017 Indonesian Food Technologists All rights reserved

This is an open access article under the CC BY-NC-ND

license

doi: 10.17728/jaft.35 Heavy metals have potentially detrimental impacts on the whole body or

on certain organs. They may induce various sorts of severe disorders, including neuro-, nephro-, carcino-, terato-, and immunological. Humans are exposed to them by breathing, eating, and drinking. Especially, the water sources from which drinking water is derived can represent a route of transmission of heavy metals to the humans. Therefore, waterborne heavy metals even at trace level have become a concern all across the world, including Turkey. The objective of this study was to investigate the elemental concentrations of nine major heavy metals (B, Cr, Ni, Cu, As, Cd, Sb, Hg and Pb) in 125 water samples (25 samples of each of plastic-bottled, glass-bottled, natural mineral, tap and well water) from Istanbul, Turkey using ICP-MS method. Sample preparation and analytical procedure were conducted according to the methods of EPA-3005A and EPA-6020A. Descriptive statistics and associations between the elemental levels in the sampling groups were evaluated by one-way ANOVA using SPSS-19 statistical package programme (P-value<0.05). Our study demonstrated that analyses showed a large range in concentration for most of the elements. Overall, 91.2% of all the waters analysed fell within the Guideline values recommended by the Ministry of Health in Turkey. However, 8.8% of the samples (7 natural mineral water, 2 tap water, 2 bottled-water and 1 well water) for B, and 0.8% of the samples (1 well water) for Ni were above the safe limits. Based on the order of elemental concentrations, plastic-bottled waters had B > Cu > As > Ni > Pb > Cr > Sb > Cd, glass-bottled waters had B > As > Cu > Ni > Cr > Sb > Pb > Cd, natural mineral waters had B > Cu > As > Ni > Cr > Sb > Hg > Pb > Cd, tap waters had B > Cu > As > Ni > Cr > Pb > Sb > Hg > Cd, and well waters had B > Cu > Ni > As > Cr > Pb > Hg > Sb > Cd. Statistically, there was a positive and significant correlation existing between Ni, Cd, Sb and Pb in the waters, which indicated towards their common source of origin. In conclusion, our study indicated that there was low-to-moderate heavy metal contamination in all the drinking- and well- water samples.

Introduction

Anthropogenic inputs like industrialization, rapid urbanization, over dependency on fossil fuels, industrial and agricultural wastes, domestic effluents, and mining are increasing the concentration of heavy metals in the environment (Karadede and Ünlü, 2000; Annadurai et al., 2002; Dorne et al., 2011). Although this fact has been well-known for several decades, exposure to heavy metals continues, and is even increasing in some areas of the world (Järup, 2003).

Heavy metals account for severe mortality and morbidity (Annadurai et al., 2002; Tchounwou et al.,

2012). Risks of heavy metals are extremely high on human body or on certain organs because they can bioaccumulate in lipids and gastrointestinal system, induce multiple organ damages, cancer, oxidative deterioration of biological macromolecules, neurological system damage, and other diseases (Chowdhury et al., 2016; Singh and Kumar, 2017).

world) (Mamtani et al., 2011). For instance, Pb caused 3% of cerebrovascular disease burden (143,000 deaths and 8.9 million disability adjusted life years). One disability adjusted life year (DALY) is equivalent of one-lost year of healthy life (WHO, 2010). In the year 2001, As-contaminated drinking water in In Bangladesh led to 9,100 deaths and 125,000 disability adjusted life years. Similarly, among fishing populations, between 1.5/1000 and 17/1000 children showed cognitive impacts due to consumption of fish containing Hg (Prüss-Ustün et al., 2011).

Humans are exposed to heavy metals via a wide range of pathways, including breathing, eating, and drinking (Jaishankar et al., 2014). Especially, heavy metal intake through drinking water may not receive enough attention because of low elemental concentration present in drinking water. However, high rate of drinking water intake raises the dose of heavy metal exposure (Ab Razak et al., 2015)

Istanbul is the biggest city in Turkey (Bingöl et al., 2013). It is also one of the largest agglomerations in Europe, and the fifth largest city in the world in terms of population of over 14.6 million. For municipal use, a volume of 2.5 million m³ of domestic water a day from surface-water-feeding reservoirs in European side and Anatolian side is supplied to Istanbul after treated in 18 water treatment facilities. In addition to the tap water, other sources of drinking for Istanbul are different brands of commercially bottled waters and natural mineral water produced in the different regions of Turkey. Generally, well water is widely used for many different purposes by humans in Istanbul (Governorship of Istanbul, 2016).

In this study, we aimed to investigate the elemental concentrations of nine major heavy metals (B, Cr, Ni, Cu, As, Cd, Sb, Hg and Pb) in 125 water samples (25 samples of each of plastic-bottled, glass-bottled, natural mineral, tap and well water) from Istanbul, Turkey using ICP-MS method.

Materials and Methods

Study Area

Twenty-five locations were selected as the study area. Sampling locations in European side (n=12) were Arnavutköy, Avcılar, Bağcılar, Bakırköy, Silivri, Beylikdüzü, Hadımköy, Beşiktaş, Çatalca, Esenler, Fatih, Kâğıthane and Sarıyer, while Kadıköy, Beykoz, Üsküdar, Kartal, Pendik, Tuzla, Ümraniye, Sultanbeyli, Çekmeköy, Ataşehir, Adalar and Şile in Anatolian side (n=13).

Sample Collection

During the period of September 2016 to December 2016, One hundred and twenty-five water samples (25 samples of each of plastic-bottled, glass-bottled, natural mineral, tap and well water) were randomly collected. Ten ml of each of tap water and well water was taken into 15 ml-Falcon tube, and tube was tightly covered. On the other hand, all the bottled waters, including natural mineral water were kept in their original packaging. Following that, all the samples were transferred to the Laboratory in a thermobox container at 4˚C for ICP-MS analysis.

Sample Preparation

Prior to analysis, digestion was conducted based on the method of EPA 3005A-Acid Digestion of Waters for Total Recoverable or Dissolved Metals for Analysis by FLAA or ICP-Spectroscopy. Each sample was acidified with 2 ml of nitric acid (Merck, Turkey) and 5 ml of hydrochloric acid (Merck, Turkey), followed by heating at 90-95˚C on a heating table (IKA, Germany) until it was substantially reduced in volume by 1/5. The digestate was cooled down in room conditions. After cooling, it was filtered through a 0.45-µm filter paper. Finally, it was diluted up to 100 ml by adding enough reactive water.

Table 1. Criteria Set Out in the Regulation Concerning Water Intended for Human Consumption by the Ministry of Health in Turkey

Element Symbol Max. limit

Boron B 1 ppm

Chromium Cr 50 ppb

Nickel Ni 20 ppb

Copper Cu 2 ppm

Arsenic As 10 ppb

Cadmium Cd 5 ppb

Antimony Sb 5 ppb

Mercury Hg 1 ppb

Lead Pb 10 ppb

Determination of B, Cr, Ni, Cu, As, Cd, Sb, Hg, and Pb by ICP-MS

Each digested sample was analysed for B, Cr, Ni, Cu, As, Cd, Sb, Hg, and Pb by an ICP-MS (Agilent 7700X, Agilent, Turkey) based on the method of EPA 6020A-Inductively Coupled Plasma-Mass Spectrometry. Serial dilution of each of the targeted heavy metals was used for construction of calibration curves. Measurements were evaluated based on the criteria set out in the Regulation Concerning Water Intended for Human Consumption by the Ministry of Health in Turkey (Table 1).

Statistical Analysis

Associations between the elemental levels in the sampling groups were evaluated by one-way ANOVA using SPSS-19 statistical package programme (P-value<0.05).

Results and Discussion

Our study revealed that analyses showed a large range in concentration for most of the elements. Overall, 91.2% of all the waters analysed fell within the Guideline values recommended by the Ministry of Health in Turkey. However, 8.8% of the samples (7 natural mineral water, 2 tap water, 2 bottled-water and 1 well water) for B, and 0.8% of the samples (1 well water) for Ni were above the safe limits (Table 2).

Evaluation by Element Boron (B)

Except for seven natural mineral waters (1.318 ppm, 1.701 ppm, 2.292 ppm, 2.297 ppm, 2.942 ppm, 3.075 ppm, and 4.331 ppm), two tap waters (2.613 ppm from European side and 3.260 ppm from Anatolian side), one plastic-bottled water (2.411 ppm), one glass-bottled water (3.234 ppm), and one well water from Anatolian side (1.393 ppm), 91.2% of the water samples were below permissible limit (<1 ppm). Range of variation was 0-3.260 ppm in tap water, 0-2.411 ppm in plastic-bottled water, 0-3.234 ppm in glass-bottled water, 0.003-4.331 ppm in natural mineral water, and 0-1.393 ppm in well water. B concentration in water is largely dependent on its leaching from the surrounding geology and wastewater discharges. It is also released from agriculture, fuel wood burning, power generation using coal and oil, glass product, manufacture, domestic and industrial use of borates/perborates, borate mining/processing, leaching of treated wood/paper, and sewage/sludge disposal (El-Harouny et al., 2009). Acute exposure to B is associated with short-term irritant effects of the upper respiratory tract and reproductive systems (Yazbeck et al., 2005). According to the Guidelines for Drinking-Water Quality by WHO, B concentrations for water bodies in Turkey are documented as 0.01-7 ppm. In most parts of the world, concentration range of B in drinking water is between 0.1-0.3 ppm. Therefore, our results were similar to the facts by WHO.

Chromium (Cr)

Range of variation of Cr was 0-0.378 ppb in tap water, 0.-0.628 ppb in plastic-bottled water, 0-1.396 ppb in glass-bottled water, 0-7.003 ppb in natural mineral water, and 0-1.354 ppb in well water. Maximum permissible level of Cr to be released into waterways is 50 ppb. Its level in drinking water is much lower. A level higher than 3 ppb indicates industrial pollution (Smith, 2008). According to the International Research Cancer (IARC), inhalation of Cr can cause human lung cancer, while human ingestion of Cr may increase the risk of stomach cancer (Smith and Steinmaus, 2009). In Turkey, Tuzen and Soylak (2006) found that Cr in drinking water samples of Tokat was below maximum

tolerable limits. In our study, highest concentration of Cr was detected in natural mineral water, glass-bottled water, well water, plastic-bottled water, and tap water. All the concentrations were within the safe limit (<50 ppb).

Nickel (Ni)

Range of variation of Ni was 0-14.766 ppb in tap water, 0-7.763 ppb in plastic-bottled water, 0-5.688 ppb in glass-bottled water, 0-17.733 ppb in mineral water, and 0-30.058 ppb in well water. Among the samples, only one well water (0.8%) was not within the safe limit. Ni is a known haematotoxic, immunotoxic, neurotoxic, genotoxic, reproductive toxic, pulmonary toxic, nephrotoxic, hepatotoxic and carcinogenic agent. It binds to specific proteins and/or amino acids in blood serum and placenta. Primary source of Ni in drinking water is leaching from metals in contact with drinking water, such as pipes and fitting. Leaching of Ni from Cr-Ni stainless steel pipework into drinking water diminished after a few weeks; as Cr was rarely found at any time in the water, this indicates that the leakage of Ni is not of corrosive origin, but rather attributable to passive leaching of Ni ions from surface of pipes (Schwenk, 1992). It may also be present in some ground waters due to dissolution from Ni ore-bearing rocks. Ni in drinking water in the United States generally range from 0.55 to 25 ppb, and average between 2 and 4.3 ppb (Das et al., 2008). In Europe, reported Ni concentrations in drinking water were generally below 10 ppb (IPCS, 1991). In Turkey, Tuzen and Soylak (2006) found that Ni in drinking water of Tokat was below tolerable limit. Another study by Bingöl et al (2013) provided that Ni was the highest concentration in waters around Kocaeli. Savcı and Bağdatlı (2015) found that Ni was within permissible limit in tap water samples from Yozgat. Our study showed that waters in Istanbul, except for only one well water, were safe for Ni.

Copper (Cu)

Range of variation of Cu was 0-0.017 ppm in tap water, 0-0.019 ppm in plastic-bottled water, 0-0.020 ppm in glass-bottled water, 0.003-0.018 ppm in natural mineral water, and 0-0.060 ppm in well water. All Cu levels were within the safe limit (<2 ppm). Cu is actually

Table 2. Average Heavy Metal Levels in Drinking- and Well Water Samples

Type

Water Parameter

B [ppm]

Cr [ppb]

Ni [ppb]

Cu [ppm]

As [ppb]

Cd [ppb]

Sb [ppb]

Hg [ppb]

Pb [ppb]

Tap water (n=25)

Average 0.260 0.098 0.939 0.003 1.535 0.009 0.026 0.018 0.084

Std. deviation 0.811 0.110 3.079 0.004 1.895 0.018 0.090 0.043 0.142

Plastic-bottled (n=25)

Average 0,105 0,186 0,511 0,002 0,593 0,039 0,107 0,024 0,271

Std. deviation 0,481 0,186 1,624 0,004 1,127 0,129 0,344 0,054 1,310

Glass-bottled (n=25)

Average 0,140 0,119 0,283 0,002 2,866 0,014 0,021 0,000 0,020

Std. deviation 0,645 0,283 1,149 0,004 2,255 0,020 0,069 0 0,048

Natural mineral (n=25)

Average 0,818 0,715 0,942 0,003 1,706 0,014 0,263 0,167 0,042

Std. deviation 1,273 1,423 3,572 0,005 2,200 0,025 0,755 0,287 0,122

Well water (n=25)

Average 0,134 0,290 1,598 0,005 0,822 0,004 0,006 0,029 0,095

Std. deviation 0.323 0.377 6.097 0.012 0.940 0.013 0.028 0.067 0.319

an essential element to human life, but chronic exposure to Cu may result in anemia, liver, abdominal pain, vomiting, headache, nausea, diarrhea and kidney damage (Jennings et al., 1996). In Turkey, Tanır et al. (2011) revealed that Cu concentration was above tolerable limit in tap water stations of Adana. Demir et al. (2015) found high levels of Cu (2.1–11.5 ppm) in tap waters of Tunceli. On the other hand, a study by Tuzen and Soylak (2006) showed that Cu in tap water of Tokat was below maximum tolerable limit. Ongen et al. (2008) determined that Cu (max. 47.93 ppb) levels from 30 municipal wells in Çorlu were under standards, which would harm people health. Similarly, Savcı and Bağdatlı (2015) determined Cu concentrations in tap water from Yozgat were within permissible limit. Ince et al. (2008) studied Cu concentration in natural mineral waters sold in Turkey, and found the ranges of 0.4 to 18.0 ppb, which were very close to our results. Our results of Cu indicated that the analysed waters were not highly polluted by industrial wastes, and for tap waters, drinking water supply system in Istanbul was in good condition.

Arsenic (As)

Range of variation of As was 0.146-6.094 ppb in tap water, 0-4.387 ppb in plastic-bottled water, 0-7.017 ppb in glass-bottled water, 0-8.666 ppb in mineral water, and 0-4.391 ppb in well water. As concentrations in the analyzed waters did not exceed the permissible limit (<10 ppb). Natural As in ground water at concentrations above drinking water standard of 10 ppb is not common (Rose et al., 2007). Well water contaminated by natural sources such as bedrock containing As has been reported to be the cause of As toxicity throughout the world. As in drinking water has attracted much attention since recognition in the 1990s of its wide occurrence in well water in Bangladesh (WHO, 2001). Chronic exposure to As can cause skin pigmentation changes, palmar and plantar hyperkeratosis, gastrointestinal symptoms, anaemia, and liver disease (Hall, 2002). As pollution has become an important topic in the agenda of the world, including Turkey. In Turkey, high level of As has been detected in drinking water supply systems. Tokar and Caylak (2011) provided that As concentration in tap water of Çankırı (1.25-55.77 ppb) exceeded the permissible level. Similarly, Demir et al. (2015) found high levels of As (10.5–78.0 ppb) in tap waters of Tunceli. Our study revealed that As levels in the water samples were within the safe limit of maximum 10 ppb despite the water reservoirs in Istanbul are stressed by intensive urban settlement, industry, and farms (Baba and Tayfur, 2011).

Cadmium (Cd)

Range of variation of Cd was 0-0.060 ppb in tap water, 0-0.616 ppb in plastic-bottled water, 0-0.059 ppb in glass-bottled water, 0-0.113 ppb in natural mineral water, and 0-0.058 ppb in well water. All samples were below the permissible limit (<5 ppb). Cd intoxication can lead to kidney, bone, and pulmonary damages. Contamination of drinking water may occur due to presence of Cd as an impurity in the zinc of galvanized pipes or Cd-containing solders in fittings, water heaters,

water coolers and taps. Phosphate fertilizers also show a big Cd load (Godt et al., 2006). In the World, median concentrations of dissolved Cd measured at 110 stations were less than 1 ppb. The maximum value recorded being 100 ppb in Peru only (WHO/UNEP, 1989). In Turkey, Ongen et al. (2008) found that Cd (max. 2.14 ppb) levels from 30 municipal wells in Çorlu were under

standards. Our study showed that maximum

concentration of Cd in the analysed samples were below the concentration of 1 ppb around the world given by WHO/UNEP.

Antimony (Sb)

Range of variation of Sb was 0-0.359 ppb in tap water, 0-1.684 ppb in plastic-bottled water, 0-0.258 ppb in glass-bottled water, 0-3.443 ppb in natural mineral water, and 0-0.140 ppb in well water. All samples were below the permissible limit (<5 ppb). Sb is available in the earth’s crust, and used for some industrial applications such as semiconductors, infrared detectors and diodes, lead storage batteries, solder, sheet and pipe metal, bearings, castings and pewter, fire-retardant formulations for plastics, rubbers, textiles, paper and paints. Its concentration dissolved in rivers and lakes is usually less than 5 ppb, and attached to particles of dirt (Sundar and Chakravarty, 2010). Average intake of Sb from water is estimated to be roughly 5 μg/day as reported by a study (Iyengar et al., 1987). The US Environmental Protection Agency (USEPA) has set a limit of 6 ppb for Sb in drinking water (Cooper and Harrison, 2009). On the other hand, this level should not exceed 5 ppb in Turkey. Our study indicated that the examined waters were within the safe limit.

Mercury (Hg)

Range of variation of Hg was 0-0.138 ppb in tap water, 0-0.233 ppb in plastic-bottled water, 0-0.899 ppb in natural mineral water, and 0-0.140 ppb in well water. Interestingly, no Hg was detected in glass- bottled waters by ICP-MS. It is ranked third by the US Government Agency for Toxic Substances and Disease Registry of the most toxic elements on the planet. It has toxic effects on nervous, digestive and immune systems, and on lungs, kidneys, skin and eyes (WHO, 2017). Human activities have nearly tripled the amount of Hg in the atmosphere, and the atmospheric burden is increasing 1.5% per year. This leads to a progressive increase in the amount of atmospheric Hg, which enters the atmospheric-soil-water distribution cycles where it can remain in circulation for years (US Department of Health and Human Services, 1999). Current sources of human exposure to Hg included dental amalgam, thermometers, sphygmomanometer, barometers, fossil fuel emissions, incandescent lights, batteries, ritualistic practices using mercury, and incineration of medical waste (Rice et al., 2014). The concentration range for Hg in drinking water is the same as in rain, with an average of about 0.025 ppb (IPCS, 1990). Our results showed that the analysed samples were below the tolerable limit of Hg of 1 ppb.

Lead (Pb)

water, 0-6.557 ppb in plastic-bottled water, 0-0,205 ppb in glass-bottled water, 0-0.205 ppb in natural mineral water, and 0-1.497 ppb in well water. All measurements were below the safe limit of 10 ppb. Pb has adverse effects on human health such as cardiovascular effects, increased blood pressure and incidence of hypertension, decreased kidney function, reproductive problems (in both men and women), reduced growth of the fetus, and premature birth (EPA, 2017). Various sources, including lead paint and house dust contaminated by lead paint pollute soil, drinking water, and food (CDC, 2012). In the world, Pb levels in drinking water in USA and Canada were 2.8 ppb and 2.0 ppb, respectively (Levin et al., 1989; Dabeka et al., 1987). Another study in Pakistan showed that Pb concentration in drinking water exceeded WHO limit (Rasool et al., 2016). In Turkey, Tanır et al. (2011) provided Pb concentrations were above the tolerable limit in drinking water stations of Adana. In our study, Pb concentrations in the analyzed waters were below the water quality standard of 10 ppb.

Statistical Evaluation

Descriptive statistics and associations between the elemental levels in the sampling groups were evaluated by one-way ANOVA using SPSS-19 statistical package programme (P-value<0.05). Statistically, there was a positive and significant correlation existing between Ni, Cd, Sb and Pb in the waters (F=0.499 and P=0.736>0.05 for Ni, F=1.282 and P= 0.281>0.05 for Cd, F=2.053 and P= 0.091>0.05 for Sb, and F=0.664 and P= 0.618>0.05 for Pb), which indicated towards their common source of origin.

Conclusion

This study indicated that there was low-to-moderate heavy metal contamination in all the drinking- and well- water samples. The manufacturers in Turkey produce bottled-waters and city water under healthy conditions. They give importance to hygienic standards, safety and quality as well as the environment. Most of them has been registered and/or awarded with specific certificates and quality systems, including ISO EN 22000 Food Safety Management System, American National Sanitation Foundation (NSF), ISO EN 9000 Quality Management, and ISO 14001 Environment Management System. Low-moderate heavy metal contamination is safe for the people living in Istanbul. However, it does not always mean the environment of the water origin sites Istanbul residents, it does not always mean environment of the water origin sites is healthy.

Acknowledgment

Authors would like to thank to Mrs. Gizem İnal Erdem for her support to finish the ICP-MS analysis.

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