Associations between repeated measurements of childhood triclosan exposure and physical growth at 7 years

Development of a nanobody-based immunoassay for the analysis of the disinfectant triclosan in water

Triclosan (TCS), a broad-spectrum antimicrobial agent in pharmaceuticals and personal care products, necessitates environmental monitoring due to its antimicrobial properties and widespread in the environment. In this study, two anti-TCS single-domain antibodies (i.e., nanobodies, Nbs), T1 and T2, were isolated from a phage-displayed Nb library derived from a camel immunized with a mixture of TCS immunogens. The T1-based enzyme-linked immunosorbent assay (ELISA) exhibited a better sensitivity to TCS than the T2-base ELISA. Motivation at enhancing specificity, sensitivity, and stability of Nb-based immunoassays promoted exploring use of a bivalent strategy to enhance performance. The bivalent Nb T1-T1 was tandemized via a linker-(GGGGS)3- between. The thermal stability of the bivalent Nb was improved in comparison with that of a monovalent Nb. The sensitivity of T1-T1-based ELISA, with an IC50 value of 4.3 ng mL-1 of TCS, was improved approximately 2-3 fold in comparison to those of T1-or T2-based ELISAs (8.5 and 14.6 ng mL-1, respectively). The average recovery of TCS from water samples measured with T1-T1-based ELISA was in the range of 99-125 %, which correlated well with that measured by a high-performance liquid chromatography (HPLC) method (R2 > 0.99). TCS in river water samples was detected by the resultant ELISA and an HPLC method, showing a satisfactory correlation.

Prenatal exposure to a mixture of organophosphate flame retardants and infant neurodevelopment: A prospective cohort study in Shandong, China

BACKGROUND

Previous studies have suggested that prenatal exposure to organophosphate flame retardants (OPFRs) may have adverse effect on early neurodevelopment, but limited data are available in China, and the overall effects of OPFRs mixture are still unclear.

OBJECTIVE

This study aimed to investigate the association between prenatal exposure to OPFR metabolites mixture and the neurodevelopment of 1-year-old infants.

METHODS

A total of 270 mother-infant pairs were recruited from the Laizhou Wan (Bay) Birth Cohort in China. Ten OPFR metabolites were measured in maternal urine. Neurodevelopment of 1-year-old infants was assessed using the Gesell Developmental Schedules (GDS) and presented by the developmental quotient (DQ) score. Multivariate linear regression and weighted quantile sum (WQS) regression models were conducted to estimate the association of prenatal exposure to seven individual OPFR metabolites and their mixture with infant neurodevelopment.

RESULTS

The positive rates of seven OPFR metabolites in the urine of pregnant women were greater than 70% with the median concentration ranged within 0.13-3.53 μg/g creatinine. The multivariate linear regression model showed significant negative associations between bis (1-chloro-2-propyl) phosphate (BCIPP), din-butyl phosphate (DnBP), and total OPFR metabolites exposure and neurodevelopment in all infants. Results from the WQS model consistently revealed that the OPFR metabolites mixture was inversely associated with infant neurodevelopment. Each quartile increased in the seven OPFR metabolites mixture was associated with a 1.59 decrease (95% CI: 2.96, -0.21) in gross motor DQ scores, a 1.41 decrease (95% CI: 2.38, -0.43) in adaptive DQ scores, and a 1.08 decrease (95% CI: 2.15, -0.02) in social DQ scores, among which BCIPP, bis (1, 3-dichloro-2-propyl) phosphate (BDCIPP) and DnBP were the main contributors.

CONCLUSION

Prenatal exposure to a mixture of OPFRs was negatively associated with early infant neurodevelopment, particularly in gross motor, adaptive, and social domains.

Interpreting the degradation mechanism of triclosan in microbial fuel cell by combining analysis microbiome community and degradation pathway

Microbes play a dominant role for the transformation of organic contaminants in the environment, while a significant gap exists in understanding the degradation mechanism and the function of different species. Herein, the possible bio-degradation of triclosan in microbial fuel cell was explored, with the investigation of degradation kinetics, microbial community, and possible degradation products. 5 mg/L of triclosan could be degraded within 3 days, and an intermediate degradation product (2,4-dichlorophen) could be further degraded in system. 32 kinds of dominant bacteria (relative intensity >0.5%) were identified in the biofilm, and 10 possible degradation products were identified. By analyzing the possible involved bioreactions (including decarboxylation, dehalogenation, dioxygenation, hydrolysis, hydroxylation, and ring-cleavage) of the dominant bacteria and possible degradation pathway of triclosan based on the identified products, biodegradation mechanism and function of the bacteria involved in the degradation of triclosan was clarified simultaneously. This study provides useful information for further interpreting the degradation mechanism of organic pollutants in mixed flora by combining analysis microbiome community and degradation pathway.