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The prevalence of breast cancer cases in Malaysia is 1 in every 20 women. Comprehending the risk factors and causation of breast cancer as well as enabling early diagnosis and treatment are important to prevent possible recurrence and fatality. Education on breast cancer plays a pivotal role in raising awareness and overcoming skepticism towards breast examination regimens. The present study aims to compare the awareness and knowledge levels between genders among the local residents of Klang Valley area, Malaysia. A cross-sectional descriptive study was conducted between October 2018 and January 2019, utilising a random convenient sampling technique. Recruitment of participants was undertaken at population-concentrated locations around the Klang Valley area. A total of 440 volunteers, 198 men and 242 women aged 18 years and above, completed the questionnaire via Google link using several electronic gadgets. Results have revealed that the majority of the residents, regardless of gender, have moderate knowledge or awareness with regard to breast cancer (76.5%), breast cancer symptoms (76.8%), and breast cancer risk factors (74.3%). However, female respondents possessed higher knowledge levels than male respondents with regard to breast cancer symptoms (p = 0.005), whereas a significant difference regarding the knowledge on breast cancer risk factors between genders is absent (p = 0.702). In terms of breast cancer screening methods, more females than males possessed sufficient knowledge about breast self-examination and mammography, constituting 50.8% and 68.2% respectively among the female demographic. Nevertheless, we perceived that the reluctance of breast examination may be due to cultural stigma and self-induced fear. This contemporary research certainly demonstrates an insufficiency of knowledge on breast cancer among the general population irrespective of gender, which further emphasises the relevance of literacy and awareness among the public to help conquer cancer.

The formation of toxic disinfection by-products (DBPs) is among the main concerns in the use of chlorine sanitizers for washing fresh and fresh-cut produce to minimize microbial cross-contamination. Even so, robust analytical methods for measuring various DBPs in produce have been lacking. This study has established two liquid-liquid extraction methods, followed by gas chromatography with electron capture detection, to measure 32 conventional and emerging DBPs in different produce types including lettuce, cabbage and strawberry. Good recoveries (50–130%) were achieved for most DBPs in the different produce. The method detection limits were in the range of 0.3–10 ng/g for trihalomethanes, haloacetic acids, nitrogenous DBPs, and other carbonaceous DBPs. Preliminary screening analysis indicated one-third of the target DBPs were found in unwashed produce, and washing with chlorine significantly promoted DBPs’ formation and concentrations in the produce. The developed analytical methods will be useful tools for future research on food DBPs.

Contamination of drinking water with pharmaceuticals and personal care products (PPCPs) is an issue of health concerns. To effectively control the level of PPCPs in drinking water, a pilot study employing two parallel trains of two-stage biofiltration, i.e., a sand/anthracite (SA) biofilter coupled with a biologically-active granular activated carbon (GAC) post-filter contactor, was conducted as a post-treatment after coagulation in a drinking water treatment plant. Results showed the biofiltration process could effectively remove PPCPs with an average removal of 53.4%, where the GAC contactor played the dominant role to remove 48.1% of the total PPCPs. The molecular properties determined the removability of individual PPCPs, i.e., smaller molecules with simpler structure connectivity were more likely to be removed. Based on the quantitative structure-property relationships (QSPRs) analysis, a simple regression model was proposed to predict the removability of each PPCP across the biofiltration process. The drinking water equivalent level (DWEL) quotient method was developed to assess the health risks of detected PPCPs in water samples. The biofiltration process showed efficient capacity to reduce the health risks of PPCPs with an average removal of 79%, and the PPCPs in the effluents generally would not pose adverse health effects. Pearson correlation analysis explored the possible role of nitrogenous PPCPs (N-PPCPs) as the precursors of nitrogenous disinfection byproducts (N-DBPs) in drinking waters. Aromatic nitrogen in PPCPs was found to be a significant descriptor for the formation potential of trichloroacetonitrile (TCAN). In addition, it was found that pre-filter chlorination could slightly improve the biofiltration of PPCPs.

Free chlorine is widely used in fresh-cut produce washing to minimize microbial cross-contamination, but its application can also lead to the formation of harmful disinfection byproducts (DBPs). This study compared DBPs in process water and washed produce during commercial operation. Samples of shredded lettuce and diced cabbages washed in chlorinated water in the traditional double-flume wash and novel immersion-free single-pass wash systems were collected at multiple time points and locations from the processing lines. A suite of 33 conventional and emerging DBPs, including 4 trihalomethanes (THMs), 9 haloacetic acids (HAAs), 9 nitrogenous DBPs (N-DBPs), and 11 carbonaceous DBPs (C-DBPs), were investigated. Overall, N-DBPs and HAAs dominated the concentration of detected DBPs. Wash water in the flumes contained 7–111 folds higher DBP levels compared to that in the single-pass system, with the abundance of DBPs following the order of N-DBPs > HAAs > C-DBPs > THMs. DBPs were detected on washed produce, presenting primarily in the forms of N-DBPs and HAAs followed by C-DBPs and THMs. While higher levels of DBPs were detected in flume-washed produce, the final potable water rinse significantly reduced the DBP concentration in these products. The concentrations of THMs and HAAs on these washed products were used to estimate potential exposure via consumption of fresh-cut produce and the levels were below the daily allowable exposure for drinking water standard established by the U.S. Environmental Protection Agency. The detected high concentration and potential toxicity of N-DBPs indicate the need for further research. The findings of this study advance the understanding of the formation and removal of DBPs during wash processes, and identify additional research opportunities for further reduction in DBPs and food safety improvement.

Chlorine sanitizers used in washing fresh and fresh-cut produce can lead to generation of disinfection by-products (DBPs) that are harmful to human health. Monitoring of DBPs is necessary to protect food safety but comprehensive analytical methods have been lacking. This study has optimized three U.S. Environmental Protection Agency methods for drinking water DBPs to improve their performance for produce wash water. The method development encompasses 40 conventional and emerging DBPs. Good recoveries (60–130%) were achieved for most DBPs in deionized water and in lettuce, strawberry and cabbage wash water. The method detection limits are in the range of 0.06–0.58 μg/L for most DBPs and 10–24 ng/L for nitrosamines in produce wash water. Preliminary results revealed the formation of many DBPs when produce is washed with chlorine. The optimized analytical methods by this study effectively reduce matrix interference and can serve as useful tools for future research on food DBPs.

Pharmaceutically active compounds (PhACs) are widely detected emerging contaminants in water environments and possess high potential risks to human health and aquatic life; however, conventional water treatment processes cannot remove them sufficiently. The boom in nanoscience and nanotechnology offers opportunities to leapfrog on the back of these new technologies to develop innovative techniques in the field of water treatment. The extraordinary properties of nanomaterials, such as large surface area, quantum effect, electrochemical and magnetic properties, and other size-dependent physical and chemical properties, offer nanotechnologies great advantages over conventional technologies. To date, nanomaterials have been extensively applied or investigated in adsorption, photocatalysis, catalytic ozonation and filtration processes and have been shown to have many promising potential application prospects. Among the various nanomaterials, graphene and carbon nanotubes have shown a superior adsorption capacity for the removal of PhACs and possess great potential for modifying photocatalysts; moreover, they can also act as highly efficient catalysts for ozonation. The nano-sized photocatalysts, i.e. nano-TiO2, graphitic carbon nitride, MoS2 nanosheets, and ZnO, generally exhibit higher photocatalytic activity than bulk photocatalysts. The involvement of nanomaterials in a membrane can improve the permeability, selectivity, and anti-fouling properties of the membrane for improved filtration processes. However, some challenges, such as high cost, poor separation performance and environmental risks, are still impeding their engineering application. Aiming to provide readers with a comprehensive insight into the application of nanotechnologies for PhACs' remediation, the current review summarizes the recent advances and breakthroughs made in nanotechnology for PhACs' removal, highlights the modification methods for improving the effectiveness of treatment methods using nanomaterials, and proposes a number of possible further research directions.

A pilot study employing two parallel trains of two-stage biofiltration, i.e., a sand/anthracite (SA) biofilter followed by a biologically-active granular activated carbon (GAC) contactor, was conducted to test the efficiency, feasibility and stability of biofiltration for removing natural organic matter (NOM) after coagulation in a drinking water treatment plant. Results showed the biofiltration process could effectively remove turbidity ( 24% of dissolved organic carbon (DOC), >57% of UV254, and >44% of SUVA254), where the SA biofilters showed a strong capacity for turbidity removal, while the GAC contactors played the dominant role in NOM removal. The vertical profile of water quality in the GAC contactors indicated the middle-upper portion was the critical zone for the removal of NOM, where relatively higher adsorption and enhanced biological removal were afforded. Fluorescence excitation-emission matrix (EEM) analysis of NOM showed that the GAC contactors effectively decreased the content of humic-like component, while protein-like component was refractory for the biofiltration process. Nutrients (NH4-N and PO4-P) supplementation applied upstream of one of the two-stage biofiltration trains (called engineered biofiltration) stimulated the growth of microorganisms, and showed a modest effect on promoting the biological removal of small non-aromatic compositions in NOM. Redundancy analysis (RDA) indicated influent UV254 was the most explanatory water quality parameter for GAC contactors’ treatment performance, and a high load of UV254 would result in significantly reduced removals of UV254 and SUVA254.

Highlights • Formation of disinfection byproducts (DBPs) by NaOCl and PAA washing was compared. • Wash water and lettuce were analyzed for 45 conventional and emerging DBPs. • PAA formed much less chlorinated DBPs than NaOCl in wash water and lettuce. • PAA formed slightly less aldehyde DBPs than NaOCl in wash water and lettuce. • The DBPs formation patterns varied in wash water compared to washed lettuce., Sodium hypochlorite (NaOCl) and peracetic acid (PAA) are being used for sanitization in food processing, but their chemical behaviors regarding disinfection byproducts (DBPs) formation during washing processes are still largely unknown. This study compared these two sanitizers in simulated washing processes for fresh-cut lettuce. Different doses of sanitizers were applied, and the wash water and washed lettuce were extracted and analyzed for 45 conventional and emerging DBPs of concern. Overall, washing by PAA generated much less DBPs than washing by NaOCl in both wash water and lettuce. Interestingly, the formation potentials of different groups of DBPs varied considerably in wash water versus in washed lettuce. This study is among the first to compare the two sanitizers for that many DBPs in both produce and wash water. The comprehensive data will facilitate the development of safer produce sanitization processes, and guide further research on DBPs in food.

Pharmaceuticals and personal care products (PPCPs) in swimming pool water are hypothesized to originate from fill water and anthropogenic sources like urine, sweat, swimwear and body surfaces. However, research exploring PPCP origins in pools is lacking. This research investigates PPCP sources at 31 swimming pools. Pool water was analyzed for 24 representative PPCPs using advanced liquid chromatography-mass spectrometry techniques. Fill water was analyzed as a contamination source and to determine if swimmers introduce PPCPs to pools. Results show every PPCP in fill water was present in pools except one, suggesting fill water is a PPCP source at pools. The presence of the antidepressant fluoxetine in 26% of pools and 0% of fill water indicates swimmers introduce pharmaceuticals. The flame retardant (tris(2-carboxyethyl)phosphine (TCEP)) was present 48% more frequently in pool than fill water, suggesting TCEP is introduced by body surfaces or swimwear. Enforcing showering and bathroom breaks is recommended to reduce PPCP contamination from swimmers.

The removal of precursors of 36 disinfection byproducts (DBPs) in effluents from flocculation/sedimentation process was evaluated across a pilot-scale two-stage biofiltration process, i.e., a sand/anthracite (SA) biofilter (empty bed contact time (EBCT) of 7.5 min) coupled with a biologically-active granular activated carbon (GAC) contactor (EBCT of 15 min). The biofiltration process exhibited a good capacity for removal of the total DBP formation potential (DBPFP) (by 25.90 ± 2.63%), and GAC contactors contributed most to the DBPFP removal (accounting for 60.63 ± 16.64% of the total removal). The removal percentage of DBPFPs of different structure types was in the following order: halonitroalkanes (58.50%) > haloaldehydes (33.62%) > haloacetic acids (HAAs, 28.13%) > haloalkanes (20.46%) > haloketones (13.46%) > nitrosamines (10.23%) > halonitriles (-8.82%) > haloalkenes (-9.84%). The precursors of bromo-DBPs (containing only bromine atoms) and maximal halogenated DBPs (containing 3 & 4 halo atoms) were removed largely compared to other DBPs. Among the total DBPFP, trihalomethanes (THMs), HAAs, and chloral hydrate were the dominant DBPs, and they accounted for >92% of the total targeted DBPs by weight. Pearson correlation analysis (CA) and principal components analysis (PCA) indicated a significant association among these dominant DBPs. Canonical correspondence analysis (CCA) revealed specific ultraviolet absorbance (SUVA254) could serve as a good surrogate parameter for DBPFP. Pre-chlorination upstream of the biofilters may not greatly impact the overall removal of DBPFP by SA/GAC biofiltration. In addition, results showed that SA/GAC biofiltration was a useful procedure to remove the inorganic DBP chlorite.

Ketamine has been increasingly used both recreationally and medicinally around the world. Although the metabolic pathways to form its metabolite norketamine have been carefully investigated in humans and animals, knowledge of their environmental occurrence and fate is limited. In this study, we investigated the occurrence of ketamine and norketamine in 20 natural bodies of water, effluents from 13 hospitals, two wastewater treatment plants and one water supply plant. Ketamine was found at concentrations as high as 10 μg/L. Ketamine and norketamine were consistently found in similar concentrations (ketamine/norketamine ratio: 0.3-4.6) in the collected water samples, and this ratio similar to that found in urine samples. Dark incubation experiments have shown that ketamine is not susceptible to microbial degradation or hydrolysis. Phototransformation was demonstrated to significantly reduce the concentration of ketamine and norketamine in river waters (t(1/2) = 12.6 ± 0.4 and 10.1 ± 0.4 h, respectively) and resulted in byproducts that are similar to human metabolites. Both direct and indirect photolysis led to the N-demethylation of ketamine to form norketamine and other byproducts, including hydroxy-norketamine (HNK), dehydronorketamine (DNK), hydroxy-ketamine (HK) and isomer forms of ketamine and norketamine. Irradiated solutions exhibited higher toxicity (via the Microtox test). Although a final risk assessment could not be made due to a lack of studies on the chronic effects on aquatic organisms, the high and persistent environmental occurrences of ketamine and norketamine as well as the increasingly acute toxicity of the photo byproducts demonstrate the importance of including metabolites in evaluation of the overall risk of ketamine.

The occurrence of antibiotics in aquatic environments has been of increasing concern around the world due to their ability to alter the structure of microbial communities and to promote the development of antimicrobial-resistant pathogens. Six major rivers in Central Taiwan were investigated for the occurrence of the eight most frequently prescribed quinolone and imidazole antibiotics using solid-phase extraction followed by high performance liquid chromatography–electrospray ionization–tandem mass spectrometry. Nalidixic acid, flumequine, ofloxacin, dimetridazole, and metronidazole were detected at 0.8–192 ng/L in the water samples. The three most frequently detected antibiotics at all sampling sites were metronidazole, nalidixic acid, and flumequine (detection frequency (n = 24) ⩾19 sites). The highest concentration of flumequine was detected at 192 ± 6.5 ng/L in the Old Zhuoshui River. Compared to the available predicted no-effect concentration data, the risk quotients of flumequine and ofloxac...