Human adenovirus in municipal solid waste leachate and quantitative risk assessment of gastrointestinal illness to waste collectors.

Leachate is a variable effluent from waste management systems generated during waste collection and on landfills. Twenty-two leachate samples from waste collection trucks and a landfill were collected from March to December 2019 in the municipality of Rio de Janeiro (Brazil) and were analyzed for Human Adenovirus (HAdV), bacterial indicators and physico-chemical parameters. For viral analysis, samples were concentrated by ultracentrifugation and processed for molecular analysis using QIAamp Fast DNA Stool mini kit® for DNA extraction followed by nested-PCR and qPCR/PMA-qPCR TaqMan® system. HAdV was detected by nested-PCR in 100% (9/9) and 83.33% (12/13) of the truck and landfill leachate samples, respectively. Viral concentrations ranged from 8.31 × 101 to 6.68 × 107 genomic copies per 100 ml by qPCR and PMA-qPCR. HAdV species A, B, C, and F were characterized using nucleotide sequencing. HAdV were isolated in A549 culture cells in 100% (9/9) and 46.2% (6/13) from truck and landfill leachate samples, respectively. Regardless of the detection methods, HAdV concentration was predicted by the quantity of total suspended solids. A quantitative microbial risk assessment was performed to measure the probability of gastrointestinal (GI) illness attributable to inadvertent oral ingestion of truck leachate, revealing the higher probability of disease for the direct splashing into the oral cavity (58%) than for the gloved hand-to-mouth (33%). In a scenario where waste collectors do not wear gloves as protective personal equipment, the risk increases to 67%. This is the first study revealing infectious HAdV in solid waste leachate and indicates a potential health risk for waste collectors.

Improving Exposure Assessment Using Non-Targeted and Suspect Screening: The ISO/IEC 17025: 2017 Quality Standard as a Guideline.

The recent advances of novel methodologies such as non-targeted and suspect screening based on high-resolution mass spectrometry (HRMS) have paved the way to a new paradigm for exposure assessment. These methodologies allow to profile simultaneously thousands of small unknown molecules present in environmental and biological samples, and therefore hold great promises in order to identify more efficiently hazardous contaminants potentially associated with increased risks of developing adverse health outcomes. In order to further explore the potential of these methodologies and push the transition from research applications towards regulatory purposes, robust harmonized quality standards have to be implemented. Here, we discuss the feasibility of using ISO/IEC 17025: 2017 as a guideline to implement non-targeted and suspect screening methodologies in laboratories, whether it is for accreditation purposes or not. More specifically, we identified and then discussed how specificities of non-targeted HRMS methodology can be accounted for in order to comply with the specific items of ISO/IEC 17025: 2017. We also discussed other specificities of HRMS methodologies (e.g., need for digital storage capacity) that are so far not included in the ISO/IEC 17025 requirements but should be considered. This works aims to fuel and expand the discussion in order to subsidize new opportunities of harmonization for non-targeted and suspect screening.

Evaluation of Viral Recovery Methodologies from Solid Waste Landfill Leachate.

Leachate from solid waste landfill is a dark liquid of variable composition and possible source of contamination of groundwater and surface waters. This study aims to assess skimmed milk flocculation and ultracentrifugation as viral concentration methods associated to different nucleic acid extraction protocols in order to establish a methodology for virus recovery from sanitary landfill leachate. Spiking experiments using human adenovirus (HAdV) and bacteriophage PP7 revealed the association of QIAamp Fast DNA Stool mini kit® nucleic acid extraction and ultracentrifugation as an effective method for recovering HAdV (346.18%) and PP7 (523.97%) when compared to organic flocculation method (162.64% for HAdV and 0.61% for PP7) that presented PCR inhibition in all undiluted samples. Ultracentrifugation applied in three landfill samples confirm efficiency of the methodology detecting HAdV in all samples with a mean of 3.44E + 06 ± 1.56E + 06 genomic copies/mL. Nucleotide sequencing characterized HAdV as belonging to group B and F. JC polyomavirus (JCPyV) was also investigated in those samples; however, detection was not observed. Methodologies for detection of viruses in leachate can be useful to generate data for future health risk analysis of workers who have contact with solid urban waste, as well as populations exposed to different environmental matrices contaminated by these effluents.

Avaliacao dos niveis de exposicao ocupacional An-Hexano, acetato de etila e tolueno em uma fábrica de fita adesiva / Evaluation of occupational exposition levels to n-hexane, ethyl acetate and toluene in factory of cellotape

Se realizó un estudio para investigar la relación entre concentraciones ambientales y los niveles de exposición individual a n-hexano, acetato de etilo y tolueno, en una industria japonesa productora de cintas addhesivas. Muestras de aire ambiental fueron colectadas a través del uso de muestradores pasivos en las cinco unidades de trabajo que componene la industria y los niveles de excposición personal fueron evaluados en 44 trabajadores de esas unidades. La determinación fueron hechas por cromatografía en fase gaseosa. Los valores de las concentraciones ambientales medias fueron de 4,82 ppm y 9,58 ppm para el n-hexano, en las dos áreas de trabajo donde era utilizado; entre 0,83 ppm y 11,41 ppm para el tolueno y entre 0,88 ppm y 5,68 ppm para el acetato de etilo, siendo que estos dos solventes fueron determinados en las cinco áreas de trabajo. Estos valores , cuando fueron comparados con aquellos obtenidos en el monitoreo individual, presentaron excelente correlación, con índice de significancia superior a 0,97. Los valores de concentración de n-hexano en el aire ambiental, cuando se compararan con aquellos obtenidos en la determinación del metabolito 2,5-hexanodiona en la orina de 16 trabajadors del sexo masculino expuestos a éste solvente, mostró una buena correlación entre ellos, mostrando una vez más la aplicabilidad del monitoreo ambiental como medio para la evaluación de la exposición/contaminación humana(AU)

Avaliacao dos niveis de exposicao ocupacional An-Hexano, acetato de etila e tolueno em uma fábrica de fita adesiva / Evaluation of occupational exposition levels to n-hexane, ethyl acetate and toluene in factory of cellotape

Se realizó un estudio para investigar la relación entre concentraciones ambientales y los niveles de exposición individual a n-hexano, acetato de etilo y tolueno, en una industria japonesa productora de cintas addhesivas. Muestras de aire ambiental fueron colectadas a través del uso de muestradores pasivos en las cinco unidades de trabajo que componene la industria y los niveles de excposición personal fueron evaluados en 44 trabajadores de esas unidades. La determinación fueron hechas por cromatografía en fase gaseosa. Los valores de las concentraciones ambientales medias fueron de 4,82 ppm y 9,58 ppm para el n-hexano, en las dos áreas de trabajo donde era utilizado; entre 0,83 ppm y 11,41 ppm para el tolueno y entre 0,88 ppm y 5,68 ppm para el acetato de etilo, siendo que estos dos solventes fueron determinados en las cinco áreas de trabajo. Estos valores , cuando fueron comparados con aquellos obtenidos en el monitoreo individual, presentaron excelente correlación, con índice de significancia superior a 0,97. Los valores de concentración de n-hexano en el aire ambiental, cuando se compararan con aquellos obtenidos en la determinación del metabolito 2,5-hexanodiona en la orina de 16 trabajadors del sexo masculino expuestos a éste solvente, mostró una buena correlación entre ellos, mostrando una vez más la aplicabilidad del monitoreo ambiental como medio para la evaluación de la exposición/contaminación humana