2.3 Contamination Status Assessment
2.3.1 Chromium concentrations in the marine environments
Polprasert et al. (1982) studied the contamination of chromium in surface sediment in the Chao Phraya River estuary, Thailand, was collected 12 sampling station. Chromium was found rang from non−detectable to 47.50 mg/kg in sediment, in the first sampling period were consistently higher than in second sampling for chromium (Table 2.2).
Censi et al. (2006) studied the contamination of chromium in surface sediment in the western past the upper Gulf of Thailand. The contamination of chromium in surface sediment ranged from 17.41−46.72 mg/kg. The Mae Klong River is the most important river in the studied area. There are all stations have enrichment factor ≤2, was associated with zero to minor contamination (Table 2.2).
Khowhit et al. (2013) studied the concentration of chromium in the sediment of the coastal area receiving effluent from Phetchaburi municipal wastewater treatment system in Phetchaburi province. The sediment samples were collected 4 sites in August 2012 and March 2013 from the bottom depth 0−15 cm. The concentration was compared to the standard of the sediment qualities coastal area. The results investigated that the average of chromium was 10.454 mg/kg dry weight, respectively which were in line and accepted with the standard qualities (Table 2.2).
Ho et al. (2010) studied the distribution of chromium in surface sediment from Ha Long Bay, Vietnam, chromium concentration in surface sediment was found approximately 27 mg/kg. The distribution pattern of chromium is controlled by organic matter and clay minerals and determined by the distribution of the fine-grained fraction in the sediments. Chromium concentration compared with sediment quality guidelines, based on the used criteria, the risk of chromium is in principle not associated with adverse biological effects. Chromium has negative values of geo−accumulation index for these reference materials, which is evaluated as unpolluted and values of enrichment factor for chromium less than 1, can be classified as minor contamination (Table 2.2).
Qiao et al. (2015) studied the chromium contamination in surface sediment was collected 18 sediment samples in the upper Gulf of Thailand and along the river of the Mae Klong, the Tha Chin, the Chao Phraya, and the Bangpakong.
Chromium concentrations ranged from 26.1−349.92 mg/kg and average is 138.94 mg/kg. The major distribution areas of chromium with higher concentrations were in the Chao Phaya River. The concentrations of chromium are higher than background data, and statistical analysis of geo-accumulation index indicates that the study area is moderately polluted by chromium (Table 2.2).
Han et al. (2016) studied the chromium contaminations in Yangtze River estuary, China, were collected sediment samples in August 2014. As a result, chromium was found approximately 34.64 mg/kg which was higher than background values. Distribution pattern of chromium was low concentration in the inner River but high in the adjacent sea area. Comparison with sediment quality guideline, chromium was within the effect range low, suggesting that chromium may cause rare adverse biological effect to local benthic organisms.
Geo-accumulation index of chromium indicated low pollution level in the Yangtze River estuary (Table 2.2).
Trifuoggi et al. (2017) studied the distribution of metals in surface sediments of Gulf of Pozzuoli, Italy. Sampling of sediments was performed aboard a boat named Antilia in December 2015 in 22 sites. The chromium concentration ranged from 0.5−49.5 mg/kg. The results investigated that the average of chromium was 14.0 mg/kg dry weight. The enrichment factor values were outstandingly high, >1.5 with values which were often ≥100. The geo−accumulation index (Igeo) was very critical for chromium showing Igeo in the range of strongly polluted (4<Igeo<5) and very strongly polluted (Igeo>5). The principal component analysis and Pearson's correlation matrix excluded significant contribution from weathering products (Table 2.2).
Xu et al. (2017) studies chromium contamination in sediment along the Jiaozhou Bay catchment, China, was collected 47 sites in December 2015. The result of chromium concentration ranged from 12.2−185.5 mg/kg with mean value 69.3 mg/kg. Values of geo−accumulation index of chromium was less than
zero, indicating minor contamination and enrichment factor values of chromium was less than 1.5, suggesting that chromium not major concern. Based on the effect−range classification according to the threshold effect level/probable effect level of sediment quality guidelines for chromium was likely to have adverse biological impacts on local aquatic ecosystems (Table 2.2).
Zhao et al. (2016) studied the concentration of chromium from the Daya Bay and adjacent shelf was determined to evaluate their levels and spatial distributions. The measured concentrations ranged from 10–85 mg/kg for chromium. Chromium contaminations, which was lower than the primary standard criteria of China, exhibited special distribution decrease from west to east of the Daya Bay. Enrichment factor and geo−accumulation index result demonstrated that chromium was not pollution level, while principal component analysis showed that chromium likely originated from natural process (Table 2.2).
Baysala and Akmanb (2018) studied the determination and evaluation of chromium in Tuzla Aydinli Bay is an important subject since it is an industrial marine area. In this study, 32 samples were collected both from near the coastal shipyard activity to far of the activity areas in Tuzla Aydinli Bay, Istanbul (Turkey). The chromium concentration ranged from 0.50–5.27mg/kg. While chromium concentration in sediment samples was determined below the recommended limit values, the risk assessment approaches on the nickel and chromium in surface sediments showed that they varied no contamination to considerable contamination (Table 2.2).
Table 2.2
The comparison of chromium (Cr) concentrations in the surface sediment of the worldwide areas.
Locations Cr concentrations (mg/kg)
References
Chao Phraya River estuary, Thailand nd−47.50 [1]
The western past the upper Gulf of Thailand 17.41−46.72 [48]
Phetchaburi province, Thailand 10.454 [49]
Ha Long Bay, Vietnam 27 [50]
The upper Gulf of Thailand 26.1−349.92 [51]
Yangtze River estuary, China 34.64 [52]
Gulf of Pozzuoli (GoP), Italy 0.5−49.5 [53]
Jiaozhou Bay catchment, China 12.2−185.5 [54]
Daya Bay and adjacent shelf 10−85 [55]
Tuzla Aydinli Bay, Istanbul (Turkey) 0.50−5.27 [56]
Remark: nd is non−detectable