[en] The polyoxometalate (POM) anion of europium (III) decatungstate [EuW₁₀O₃₆]^9- exhibits great luminescence quantum yields of approximately 67% but suffers reduced red light emissions that are due to the low ⁵D₀→⁷F₂ transmissions. Fine tuning the microenvironment around [EuW₁₀O₃₆]^9- anion through intercalation into different compositions of layered double hydroxides (LDHs) materials, greatly enhances the ⁵D₀→⁷F₂ transmissions. The positive nanosheets in LDHs provide a conducive microenvironment for strong transitions of ⁵D₀→⁷F₂ to occur. The ratio I(⁵D₀→⁷F₂)/I(⁵D₀→⁷F₁) for the observed intensities vary from 0.44 for [EuW₁₀O₃₆]^9- ion to 14.08, 6.20, 1.75 and 1.59 in Mg₂Al-EuW₁₀O₃₆, LYbH-EuW₁₀O₃₆, Zn₂Al-EuW₁₀O₃₆ and LEuH-EuW₁₀O₃₆ materials respectively (Mg₂Al = magnesium aluminum LDHs, Zn₂Al = Zinc aluminum LDHs, LYbH = layered ytterbium hydroxide LDHs, and LEuH = layered europium hydroxide LDHs). As such, these materials can find a wide application in processes that require the red light luminescence.

[en] Highlights: • Exposomics is assessment of organism exposure to pollutants using OMIC technology. • Virtual organisms were used for comparative exposomics in two Reservoirs. • Levels in Three Gorges Reservoir were higher than those in L. Victoria. • In both reservoirs, fat bioaccumulations are above set standards for aquatic life. -- Abstract: Exposomics is assessment of organism exposure to high priority environmental pollutants in an ecosystem using OMIC technologies. A virtual organism (VO) is an artificial property-tool (OMIC) reflecting exposomic process in compartments of real organisms. The exposomics of aquatic organisms inhabiting Lake Victoria (L.V.) and Three Gorges Reservoir (TGR) were compared using VOs. The two reservoirs are heavily depended on for food and water both in Africa and China. The target priority pollutants in the reservoirs were polyclic aromatic hydrocarbons (PAHs) and persistent organic pollutants such as polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), medium chain chlorinated paraffins (MCCPs) and short chain chlorinated paraffins (SCCPs). The VOs showed that in a period of 28 days, aquatic organisms in TGR were exposed to total (∑) PAHs of 8.71 × 10⁻⁶ mg/L, PCBs of 2.81 × 10⁻⁶ mg/L, OCPs of 2.80 × 10⁻⁶ mg/L, MCCPs of 8.9 × 10⁻¹⁰ mg/L and SCCPs of 1.13 × 10⁻⁷ mg/L. While in a period of 48 days, organisms in L. V. were exposed to total (∑) PAHs of 7.45 × 10⁻⁶ mg/L, PCBs of 4.70 × 10⁻⁶ mg/L, OCPs of 3.39 × 10⁻⁸ mg/L, MCCPs of 4.6 × 10⁻¹⁰ mg/L and SCCPs of 3.6 × 10⁻⁹ mg/L. The exposomic levels in TGR after 28 days were higher than those in Lake Victoria after 48 days. In both reservoirs, bioaccumulation levels are above set standards for aquatic organisms. The sources of the pollutants into the reservoirs were diagnostically determined to originate from anthropogenic processes such as petrogenic, diesel emissions, biomass burning, coal combustion, electronic wastes, traffic emissions and historic uses.