An overview of current knowledge on organophosphate di-esters in environment: Analytical methods, sources, occurrence, and behavior

Organophosphate di-esters (di-OPEs) are highly related to tri-OPEs. The presence of di-OPEs in the environment has gained global concerns, as some di-OPEs are more toxic than their respective tri-OPE compounds. In this study, current knowledge on the analytical methods, sources, environmental occurrence, and behavior of di-OPEs were symmetrically reviewed by compiling data published till March 2023. The determination of di-OPEs in environmental samples was exclusively achieved with liquid chromatography mass spectrometry operated in negative mode. There are several sources of di-OPEs, including industrial production, biotic and abiotic degradation from tri-OPEs under environmental conditions. A total of 14 di-OPE compounds were determined in various environments, including dust, sediment, sludge, water, and atmosphere. The widespread occurrence of di-OPEs suggested that human and ecology are generally exposed to di-OPEs. Among all environmental matrixes, more data were recorded for dust, with the highest concentration of di-OPEs up to 32,300 ng g-1. Sorption behavior, phase distribution, gas-particle partitioning behavior was investigated for certain di-OPEs. Suggestions on future studies in the perspective of human exposure to and environmental behavior of di-OPEs were proposed.

An overview of organophosphate esters and their metabolites in humans: Analytical methods, occurrence, and biomonitoring

With the strict regulation of brominated flame retardants, organophosphate esters (OPEs) have been extensively used as replacements. Increasing concerns on OPEs have aroused due to their extensive distribution in the environment and humans, as well as their potential toxicities. Recent studies have demonstrated that some organophosphate di-esters are even more toxic than their respective tri-esters. This review summarized the current state of knowledge on the analytical methodologies (including sample collection and preparation, instrumental analysis, and the feasibility of each potential human matrix), as well as the occurrences of OPEs and/or their metabolites (m-OPEs) in various human matrices. Organophosphate esters are readily metabolized in human thus only limited studies reported their occurrences in blood and breast milk, whereas abundant studies are available regarding the occurrences of m-OPEs rather than OPEs in urine. Since none of the matrix is suitable all the time, appropriate matrix should be selected depending on the aims of biomonitoring studies, e.g., high throughput screening or body burden estimation. Biomonitoring with non-invasive matrices such as hair and/or nail is useful to screen specific populations that might be under high exposure risks while urine is more suitable to provide valuable information on body burden. In terms of urinary monitoring, specific biomarkers have been identified for some OPE compounds, including tri(2-butoxyethyl) phosphate, tri(1,3-dichloro-2-propyl) phosphate, tri(2-chloroethyl) phosphate and tri(1-chloro-2-propyl) phosphate. Further studies are required to identify suitable urinary biomarkers for other OPE compounds, especially the emerging ones.

The effectiveness of educational programmes in promoting sun protection among children under the age of 18: a systematic review and meta-analysis

Childhood ultraviolet radiation exposure has a strong connection to the development of skin cancer in later life. Therefore, there have been numerous sun protection educational programmes targeted to this age group. However, the association between these have not been well established. This systematic review aims to summarize the evidence on, and assess, the effectiveness of educational programmes in improving sun protection among children under age-18. The protocol was prospectively registered in the PROSPERO database (CRD42020178264). Per PRISMA guidelines, bibliographic databases CENTRAL, OVID (EMBASE, MEDLINE, PsycINFO), LILACS, trial registries, grey literature and other sources were systematically searched for randomized controlled and clinical controlled trials published between database inception to 9 June 2020. Dual independent review of abstracts and full texts was performed. Eligible studies were assessed for methodological quality using the Cochrane risk-of-bias tool. The primary outcome was postintervention scores [standardized mean difference (SMD)] for sun protection (i) knowledge (ii) attitudes and beliefs (iii) behavioural intentions and behaviours. Sidik-Jonkman random effects meta-analysis, sensitivity and subgroup analyses were performed for specific outcomes (sunscreen and sun-safe hat use) which were sufficiently reported. 1350 publications were identified and 24 eligible trials, conducted across 8 different countries, with sufficient aggregate data were included. Small-to-moderate effects of educational programmes were observed across all sun protection outcomes of interest, but negligible effect sizes were demonstrated when specific outcomes were meta-analysed - sunscreen use, SMD 0.18 (95% CI 0.07-0.29; n = 8) and sun-safe hat use, SMD 0.08 (95% CI, 0.00-0.16; n = 6). A promising approach in the future may be to consider targeting children in secondary education with a digitally delivered interactive intervention. Current evidence, however, is insufficient to assess the effects of potential moderators and change in sun protection outcomes is likely not one-size-fits-all. Further research is warranted to direct intervention design and public policy.