**4. Organomercury, organotin, and organolead and their "fingerprint" on environmental compartments and surrounding biota: case study, Turda region**

The presence of these organometallic compounds surrounding us has raised a great deal of concern in the past few decades because of their high toxicity to nontarget organisms when leached into different environmental compartments, even at low concentrations [2, 23, 33]. At these moments, most studies regarding organometallic compounds present in the environment were conducted on aquatic environment. Studies considering soil or air contamination with organometallic compounds were most of the time conducted on industrial sites and mining areas. Similarly, although studies on bioconcentration and biomagnification of organometallic compounds were done on a large scale of species from the aquatic environment, according to our knowledge, there is minor information in the literature considering organometallic compounds uptake potential by vegetables.

In this work, a field study was conducted investigating the pathways of organometallic compounds (tin, lead, and mercury species) in soil-water environment and their uptake potential in vegetables grown on inhabited area—Turda region, including rural, urban, and agricultural sites considering these sites as possible contaminated areas due to the presence of an old chemical production plant (chemicals factory Turda) which was closed from more than 20 years.

## **4.1. Organic compounds analysis in environmental samples: case study, Turda region— Cluj, Romania**

Surface water as well as underground water samples were collected from the mentioned sites (rural, urban, agricultural, and industrial areas) in order to evaluate if there are any signs considering the potential of past pollution. Considering surface water samples, total 22 sampling points were selected for surface water status evaluation. Specifically, 7 sampling points were selected located on the banned industrial sites, 10 sampling points from inhabited areas (3 sampling points from Turda town and 7 sampling points from rural areas), and 5 sampling points from the agricultural place. Wells water, totally from 21 sampling sites, were collected as follows: 3 sampling points were selected located on the banned industrial sites, 14 sampling points from inhabited areas (4 sampling points from Turda town and 10 sampling points from rural areas), and 4 sampling points from agricultural place.

Organometallic compounds detected in water samples including surface and well water (underground water) showed higher levels in the samples collected from old industrial site than in the other sampling locations (inhabited area—rural and urban, and agricultural sites). The range of organotin, organolead, and organomercury amount detected in the water samples vary between 0.1 and 72, 0.2 and 15.9, and 0.08 and 61.4 µg·L−1, respectively.

Considering **Figure 2**, it could be observed that the organometallic compounds that were detected in the higher amount in the samples collected from the banned industrial area were methylmercury, ethylmercury, tetraethyllead, and triphenyltin with the average amounts of 26.8, 11.4, 19.5, and 37.7 µg·L−1, respectively.

Excluding amount value of water samples collected from the banned industrial area, higher values, with 15–20%, of monitored organometallic compounds were observed in the case of underground water samples than those of surface water samples.

Compounds, such as dimethylmercury, monoethyllead, monobutyltin, monophenyltin, and diphenyltin were detected just in 41% in the collected water samples. This could be attributed to their instability considering their physicochemical properties. Taking into account the variations between the period of sampling (March, July, and October), no significant differences were observed.

Concerning Organometallic Compounds in Environment: Occurrence, Fate, and Impact http://dx.doi.org/10.5772/67755 57

organometallic compounds were most of the time conducted on industrial sites and mining areas. Similarly, although studies on bioconcentration and biomagnification of organometallic compounds were done on a large scale of species from the aquatic environment, according to our knowledge, there is minor information in the literature considering organometallic com-

In this work, a field study was conducted investigating the pathways of organometallic compounds (tin, lead, and mercury species) in soil-water environment and their uptake potential in vegetables grown on inhabited area—Turda region, including rural, urban, and agricultural sites considering these sites as possible contaminated areas due to the presence of an old chemical production plant (chemicals factory Turda) which was closed from more than

**4.1. Organic compounds analysis in environmental samples: case study, Turda region—**

Surface water as well as underground water samples were collected from the mentioned sites (rural, urban, agricultural, and industrial areas) in order to evaluate if there are any signs considering the potential of past pollution. Considering surface water samples, total 22 sampling points were selected for surface water status evaluation. Specifically, 7 sampling points were selected located on the banned industrial sites, 10 sampling points from inhabited areas (3 sampling points from Turda town and 7 sampling points from rural areas), and 5 sampling points from the agricultural place. Wells water, totally from 21 sampling sites, were collected as follows: 3 sampling points were selected located on the banned industrial sites, 14 sampling points from inhabited areas (4 sampling points from Turda town and 10 sampling

Organometallic compounds detected in water samples including surface and well water (underground water) showed higher levels in the samples collected from old industrial site than in the other sampling locations (inhabited area—rural and urban, and agricultural sites). The range of organotin, organolead, and organomercury amount detected in the water sam-

Considering **Figure 2**, it could be observed that the organometallic compounds that were detected in the higher amount in the samples collected from the banned industrial area were methylmercury, ethylmercury, tetraethyllead, and triphenyltin with the average amounts of

Excluding amount value of water samples collected from the banned industrial area, higher values, with 15–20%, of monitored organometallic compounds were observed in the case of

Compounds, such as dimethylmercury, monoethyllead, monobutyltin, monophenyltin, and diphenyltin were detected just in 41% in the collected water samples. This could be attributed to their instability considering their physicochemical properties. Taking into account the variations between the period of sampling (March, July, and October), no significant differ-

points from rural areas), and 4 sampling points from agricultural place.

underground water samples than those of surface water samples.

26.8, 11.4, 19.5, and 37.7 µg·L−1, respectively.

ences were observed.

ples vary between 0.1 and 72, 0.2 and 15.9, and 0.08 and 61.4 µg·L−1, respectively.

pounds uptake potential by vegetables.

56 Recent Progress in Organometallic Chemistry

20 years.

**Cluj, Romania**

Analysis of soil samples, totally 29 (inhabited areas: 7 sampling points from Turda town and 14 sampling points from villages; 5 from agricultural areas; and 3 from banned industrial sites) has shown higher amounts than analysis from water samples. Soil samples were collected from horizon 0, and from 15 and 30 cm depth, respectively. Between the layers, minor decreasing tendency was observed once with decreasing the depth.

Comparing detected amounts of organomercury compounds of soil samples from a rural area with those of wells water from the same region (**Figure 3**), it was observed that the average value of all four monitored organomercury compounds were approximately twofold higher in the case of soil samples than in well water (underground water).

**Figure 3.** Organomercury compound variation in underground water (wells) and soil from rural sites.

Organotin compounds were detected at a higher percentage in samples from the industrial area compared to the rest of sampling locations (urban, rural, or agricultural areas). Monobutyltin and monophenyl tin were detected just in 40% of the collected samples including water and soil samples from all sampling sites. This could be caused by their weak stability in the environment.

According to **Figure 4**, the average values of organotin compounds increase once with increasing their degree of alkylation in both the case of water as well as soil samples. In soil samples collected on depth layers, in most cases the organotin compounds were extremely lower in the surface horizons and the amount starts to increase once with depth (see **Figure 4**).

The total amount of organotin compounds in water and soil samples collected from the banned industrial site vary between 38 and 364.1 ppm while from the rest of sampling location the total amount of organotin compounds vary between 3.4 and 21.5, 1.6 and 31.5, and 1.4 and 28.9 ppm.

With regard to organolead compounds, no correlation was found between the detected amounts and sampling locations, as shown in **Table 2**.

## **4.2. Organometallic compounds uptake by vegetables grown on possible contaminated sites: case study, Turda region—Cluj, Romania**

The major pathway of living organism's exposure to contaminants in soil is through food ingestion (food web). The prediction or estimation of risks to living organisms requires knowledge about both environmental contamination and food contamination. The direct measurement of contaminant concentration in living organisms' food is advisable to minimize uncertainty in ecological risk assessment [45]. However, site-specific data on the bioaccumulation of contaminants in vegetation and other biota that comprise living organisms diet are often not available because of constraints in funding and/or time, most of the analysis being expensive and time-consuming.

Most time, the concentration of chemical contaminants is measured at the known contaminated sites prior to a risk assessment. The challenge for the development of numerical models that are able to estimate the concentration of contaminants accumulated in plants (as vegetables, crops, etc.) is the soil-plant uptake factor. Soil-plant uptake factor refers to the ratio of a contaminant in plants to that in soil. The concentration of a contaminant in plant at a particular location is estimated by multiplying the measured concentration in soil by the soil-plant uptake factor [45].

Usually, the concentrations of monitored contaminant in mature plants and soil are assumed to be at equilibrium, thus exposure time is not necessary to be considered. However, in nature the bioavailability of organometallic compounds depend on the geochemical nature, pedoclimatic variables (temperature and rain intensity) and related to fluctuations of physicochemistry of the medium, such as soil moisture, pH, and soil organic matter content [46]. On the other side, the bio-uptake process depends on the internalization pathways of plant species which refer to the ability of organometallic compounds to cross the biological barrier. That, most of the time, is determined by the concentration of flux of internalized organometallic compounds but studied has showed that this ability of plants depends also on their size, nature, and physiology.

Organotin compounds were detected at a higher percentage in samples from the industrial area compared to the rest of sampling locations (urban, rural, or agricultural areas). Monobutyltin and monophenyl tin were detected just in 40% of the collected samples including water and soil samples from all sampling sites. This could be caused by their weak

According to **Figure 4**, the average values of organotin compounds increase once with increasing their degree of alkylation in both the case of water as well as soil samples. In soil samples collected on depth layers, in most cases the organotin compounds were extremely lower in

The total amount of organotin compounds in water and soil samples collected from the banned industrial site vary between 38 and 364.1 ppm while from the rest of sampling location the total amount of organotin compounds vary between 3.4 and 21.5, 1.6 and 31.5, and

With regard to organolead compounds, no correlation was found between the detected

**4.2. Organometallic compounds uptake by vegetables grown on possible contaminated** 

The major pathway of living organism's exposure to contaminants in soil is through food ingestion (food web). The prediction or estimation of risks to living organisms requires knowledge about both environmental contamination and food contamination. The direct measurement of contaminant concentration in living organisms' food is advisable to minimize uncertainty in ecological risk assessment [45]. However, site-specific data on the bioaccumulation of contaminants in vegetation and other biota that comprise living organisms diet are often not available because of constraints in funding and/or time, most of the analysis

Most time, the concentration of chemical contaminants is measured at the known contaminated sites prior to a risk assessment. The challenge for the development of numerical models that are able to estimate the concentration of contaminants accumulated in plants (as vegetables, crops, etc.) is the soil-plant uptake factor. Soil-plant uptake factor refers to the ratio of a contaminant in plants to that in soil. The concentration of a contaminant in plant at a particular location is estimated by multiplying the measured concentration in soil by the soil-plant uptake factor [45].

Usually, the concentrations of monitored contaminant in mature plants and soil are assumed to be at equilibrium, thus exposure time is not necessary to be considered. However, in nature the bioavailability of organometallic compounds depend on the geochemical nature, pedoclimatic variables (temperature and rain intensity) and related to fluctuations of physicochemistry of the medium, such as soil moisture, pH, and soil organic matter content [46]. On the other side, the bio-uptake process depends on the internalization pathways of plant species which refer to the ability of organometallic compounds to cross the biological barrier. That, most of the time, is determined by the concentration of flux of internalized organometallic compounds but studied has showed that this ability of plants depends also on their size,

the surface horizons and the amount starts to increase once with depth (see **Figure 4**).

stability in the environment.

58 Recent Progress in Organometallic Chemistry

1.4 and 28.9 ppm.

amounts and sampling locations, as shown in **Table 2**.

**sites: case study, Turda region—Cluj, Romania**

being expensive and time-consuming.

nature, and physiology.

**Figure 4.** Organotin compound variation between soil (layers) and water samples collected from the sampling points of banned industrial sites.

The uptake factor of monitored organometallic compounds varied between plants (considering their edible part contact with contaminated environmental matrix), see **Table 3**. With respect to their fates in relationship to plant uptake, organometallic compounds in soil can be roughly divided into three groups according to their uptake factors: lowest average uptake



**Organolead compounds**

**Sample type No.**

Banned

Soil

3

0.1–34.2 12.8

–

0.5–21.5 8.6

–

0.4–7.2

3.8

1

0.5–4.9

0.8

1

industrial site

(µg·kg−1)

Surface

7

0.2–18.5 5.9

3

0.3–15.5 6.7

2

0.4–10.8 3.9

2

0.4–5.1

1.2

4

60 Recent Progress in Organometallic Chemistry

water

(µg·L−1)

Well

3

0.2–25.8 11.5

1

0.4–18.2 7.1


0.3–6.9

2.4

1

0.5–3.8

0.9

2

waters

(µg·L−1)

Urban site

Soil

7

0.5–10.2 3.5

2

1.2–13.5 6.5

1

0.5–11.8 3.2

2

1.5–5.9

1.8

2

(µg·kg−1)

Surface

3

0.2–8.7

2.9

–

0.8–9.2

2.8

–

0.2–5.9

1.8

1

0.4–3.5

0.7

1

water

(µg·L−1)

Well

4

0.4–12.6 4.5

–

0.4–5.5

3.1

–

0.4–9.7

2.3

1

0.2–4.9

2.5

1

waters

(µg·L−1)

Rural site

Soil

14

0.3–21.8 10.5

3

0.5–16.2 5.8

2

0.2–7.4

3.8

4

1.2–6.2

2.6

6

(µg·kg−1)

Surface

7

1.2–15.5 5.5

2

0.2–6.7

2.1

1

0.4–4.2

1.5

2

0.4–3.9

0.8

3

water

(µg·L−1)

Well

10

2.8–16.7 8.2

4

0.4–15.5 3.9

3

0.4–6.1

3.1

2

0. –6.2

3.5

4

waters

(µg·L−1)

**Range**

**Average**

**N.S.U.D.**

**Range**

**Average**

**N.S.U.D.**

**Range**

**Average**

**N.S.U.D.**

**Range**

**Average**

**N.S.U.D.**

**TEL**

**TREL**

**DEL**

**MEL**

**Table 2.** Organolead species variation between sampling sites.

compounds was not detected.



factor (between 0.001 and 0.05), medium average uptake factor (0.05–0.1), and highest average uptake factor (0.1–1). The highest uptake factors for almost all monitored organometallic compounds were determined in the case of root and bulb vegetables, flowed by leafy vegetables, and finally by fruit vegetables (see **Table 3**).

Lowest uptake factors were determined in the case of monoethyllead, monobutyltin, monophenyltin, diphenyltin, and dibutyltin regardless of plant species group (leafy, root, bulb, fruit, and vegetables).
