Are wastewater treatment plants as the source of microplastics in surface water and soil?

Microplastics (MPs) are widely detected in wastewater treatment plants (WWTPs) and natural environment, while the relationship of MPs pollution in both media is not fully understood. In this study, the occurrence of MPs in WWTPs and in surface water and soil was investigated, and their relationship was critically formulated. Results showed although wastewater treatment could effectively remove MPs (58.2%), the effluent was still the important source of MPs in the river, while sludge was not as important as the effluent of MPs in the soil. Specifically, the dominant size ranges of MPs were 0-200 µm, with main type of PE in all wastewater, sludge, river and soil. The dominant shape of MPs in wastewater and river was film. However, the shapes were different between sludge (52.1% of fibers) and soil (40.6% of fragment). Overall, WWTP input and surface runoff were the main source of MPs pollution in surface water, and the abrasion of agricultural films accounted for the MPs pollution in soil. The findings revealed the distribution and interconnection of MPs in WWTPs and environmental media, which could help to trace the sources of MPs pollution and assess the ecological risks in the environment.

Photochlorination-induced degradation of microplastics and interaction with Cr(VI) and amlodipine.

Wastewater treatment plants (WWTPs) are the important source of microplastics (MPs) in the environment, and disinfection processes bear high potential to degrade MPs. This study investigated the physicochemical degradation, dissolved organic products and interaction with co-existed pollutants (heavy metal and pharmaceutical) on polyethylene (PE), polypropylene (PP) and polystyrene (PS) MPs during simulated disinfection processes. Compared to photo or chlorination, photochlorination significantly resulted in the physicochemical degradation, including morphology alteration, fragmentation, and chemical oxidation on PP and PS MPs, but showed relatively low effect on PE, indicating the different resistance among polymers to disinfected treatment. Photochlorination also caused the formation of chain-scission organic compounds and even chlorinated products from MPs (e.g. C11H19O4Cl for PP and monochlorophenol, dichlorophenol, chloroacetophenone and chlorobenzoic acid for PS), which may form disinfection byproducts to induce healthy risk. The adsorption potentials of MPs for Cr(VI) or amlodipine were enhanced by photochlorination since the cracking and formed oxygen functional groups enhanced the pore filling and surface precipitation of Cr(VI), and the electrostatic attraction and hydrogen bonding with amlodipine. The findings indicated the physicochemical degradation of MPs and the combined pollution with co-existed pollutants, highlighting the health risks of MP-derived organic products during the disinfection treatments (even in normal dosage) in WWTPs.

The Association of Matrix Metalloproteinase-1 Promoter Polymorphisms with Breast Cancer.

BACKGROUND/AIM: The family of matrix metalloproteinases (MMPs) are responsible for the homeostasis of extracellular matrix components and their genetic polymorphisms may be associated with cancer susceptibility. The serum levels of MMP-1 have been reported to be lower in breast cancer patients than healthy subjects. In the current study, we aimed at investigating the contribution of a polymorphism in the promoter region of MMP-1 to breast cancer in Taiwan. MATERIALS AND METHODS: The MMP-1 rs1799705 polymorphic genotypes were genotyped among 1,232 breast cancer patients and 1,232 healthy controls by the typical polymerase chain reaction-restriction fragment length polymorphism methodology. RESULTS: The percentages of 2G/2G, 1G/2G, and 1G/1G for MMP1 -1607 genotypes were 35.4, 40.6 and 24.0% in the breast cancer group and 34.1, 43.6, and 22.3% in the healthy control group (p trend=0.3025), respectively. The odds ratios (ORs) after adjusting for age, smoking and alcohol drinking status for those carrying 1G/2G and 1G/1G genotypes at MMP1 -1607 were 0.93 (95%CI=0.76-1.11, p=0.2390) and 1.01 (95%CI=0.77-1.23, p=0.7377), respectively, compared to those carrying the wild-type 2G/2G genotype. Supporting this finding, the adjusted OR for those carrying the 1G allele at MMP-1 -1607 was 1.03 (95%CI=0.91-1.18, p=0.8860), compared to those carrying the wild-type 2G allele. Our findings suggest that the polymorphic genotypes at MMP1 promoter -1607 investigated in the current study, may not play a major role in determining cancer susceptibility to breast cancer in Taiwan. Other early diagnostic and predictive markers are urgently needed for personalized and precise breast cancer detection and therapy.

The Association of Matrix Metalloproteinase-8 Promoter Genotypes in Breast Cancer.

BACKGROUND/AIM: The family of matrix metalloproteinases (MMPs) controls homeostasis of the extracellular matrix and their genetic polymorphisms may be associated with personal cancer susceptibility. The serum levels of MMP8 was reported to be higher in patients with breast cancer than in healthy individuals. In this study, we aimed to investigate the contribution of a polymorphism in the promoter region of MMP8 (-799C/T) and two nonsynonymous polymorphisms (Val436Ala and Lys460Thr) to breast cancer. MATERIALS AND METHODS: MMP8 -799C/T, Val436Ala and Lys460Thr polymorphic genotypes were determined for 1,232 patients with breast cancer and 1,232 healthy controls by polymerase chain reaction-restriction fragment length polymorphism methodology. RESULTS: The odds ratios (ORs) after adjusting for age, gender, smoking and alcohol drinking status for those carrying CT and TT genotypes at the MMP8 promoter C-799T were 1.03 (95% CI=0.88-1.23, p=0.7475) and 1.08 (95% CI=0.91-1.53, p=0.3561), respectively, compared to those carrying the wild-type CC genotype. The OR for the combined T-bearing genotypes were of a similar non-significant level (OR=1.05, 95% CI=0.90-1.26, p=0.5176). Supporting this finding, the adjusted OR for those carrying the T allele at MMP8 C-799T was 1.05 (95% CI=0.86-1.21, p=0.3797), compared to those carrying the wild-type C allele. There was also no significant association of MMP8 Lys460Thr with breast cancer. There was no polymorphic genotype at MMP8 Val436Ala found among any of the investigated individuals. CONCLUSION: MMP8 -799C/T, Val436Ala and Lys460Thr polymorphisms may only play an indirect role in determining personal cancer susceptibility to breast cancer in Taiwan.