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Explora: Environment
and Resource Environmental contamination of titanium

Table 3. (Continued)
Country/region Source/environment Ti forms Mass concentration Particle number References
concentration (particles/L)
France Ti-based nanomaterials in TiO -based 133 – 260 μg/L - 62
2
the river downstream of a nanomaterials
nano-manufacturer industrial
site
Taihu Lake, China Ti-based nanoparticles in lake Ti in nanoparticles 0.1 – 10 μg/L (2.28 – 2.78) ×10 5 100
water
Sava River, Slovenia Ti-based nanoparticles in river TiO in 1.96 – 7.23 µg/L (0.07 – 7.0) ×10 6 63
2
water nanoparticles
Seine River watershed, Ti-based nanoparticles in TiO in 3.5 – 23.4 µg/L (9 – 900)×10 8 111
2
west of Paris, France aforested brook nanoparticles
Ti-based nanoparticles in an 1.4 – 69.6µg/L
agricultural stream
Ti-based nanoparticles in an 0.5 – 5.9µg/L
urban stream
Columbia, South Ti-based nanoparticles in TiO -engineered Lower Saluda: - 112
2
Carolina, US the surface waters of urban nanoparticles 39.2±6.7 µg/L,
watersheds (Lower Saluda Broad: 233.4±8.1 µg/L,
River, Broad River, and Congaree:
Congaree River) 5,975.7±88.8 µg/L
Abbreviations: LOD: Limit of detection; UK: United Kingdom; US: United States.

from the overlapping of electrical double layers that comparatively low Ti content was present in Laizhou
develop around the particles is determined by the surface Bay, China (1.02 – 123 mg/kg, median: 27.3 mg/kg).
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potential and surface charges. The stability ratio values are The potential factors for the large differences between Ti
usually calculated to represent the rate of aggregation in concentrations in these two sediments include organic
adispersion. Aggregation rates are normalized to those matter contents, abundance of fine fractions of sediment
observed in unstable dispersions, where particle diffusion (<63 μm), and pollution from industries and sewage
alone controls aggregation, in order to compute the discharges, as well as the occurrence of natural kaolinite
stability ratios. 117,118 minerals in the surrounding regions.
Due to the dilution effect, Ti levels in marine ecosystems As noted earlier, atmospheric deposition is another
maybe lower than in freshwater systems. Ti levels recorded natural mechanism for Ti to reach aquatic habitats. Ti
in coastal seawater samples from Canada and Norway were particles in the atmosphere can be generated from a range
10,000 ng/L and 40 – 400 ng/L, respectively, while seawater of sources, including natural dust and industrial emissions,
from Laizhou Bay, China, showed levels of Tiat 200 – such as windblown mineral dust aerosols. In addition,
199,000 ng/L (median: 820 ng/L). 101,106,107 Anincreasein agricultural activities (generate atmospheric dust),
Ti levels may occur around industrialized coastal areas airborne PM (PM /PM ), and photochemical reactions
2.5
10
or in estuaries where rivers deliver larger quantities of Ti of TiO -coated material surfaces with atmospheric water
2
from upstream sources. Suspended TiO NPs in rivers and vapor and oxygen/irradiation wave lengths are also the
2
119
seawater have various surface characteristics and particle sources of TiO in the air. These particles accumulate
2
sizes, but eventually all will sink into the river and marine in water bodies, thus increasing the total Ti content.
108
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sediments due to aggregation with organic substances. Importantly, the non-homogeneous distribution of the Ti
Therefore, the Ti concentrations in river and marine in aquatic environments is controlled by the availability
sediments could be much higher than the Ti content in of Ti minerals in the surrounding geology, the presence
the aqueous medium. Sediments in Xiangjiang River, of industrial activity, and the type of water body, either
China, showed a high Ti content of 7,400 to 58,700 mg/ freshwater or the oceans.
kg, which was largely due to the weathering of terrigenous
minerals in the surrounding environment. Ti in marine 4.2. Biogeochemistry
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sediments was observed in Xiamen Bay, China, at 2,340 In aquatic environments, Ti typically exists in the form
– 6,330 mg/kg (mean: 4,360 ± 1,480 mg/kg), while of suspended PM and is often found associated with
Volume 2 Issue 3 (2025) 11 doi: 10.36922/EER025130027