Bracken Fern Carcinogen, Ptaquiloside, Forms a Guanine -Adduct in DNA.

Bracken fern ( sp.) is a viable and vigorous plant with invasive potential, ingestion of which causes chronic illness and cancers in farm animals. Bracken is a suspected human carcinogen, and exposure can result from ingestion of bracken-contaminated water, dairy products, or meat derived from livestock grazing on bracken fern.

DNA damage in prepared semen is negatively associated with semen quality and fertilisation rate in assisted reproduction technology (ART) treatment.

Sperm DNA contains strand breaks and base damage that can potentially affect reproductive health. This study aims to determine to what extent sperm DNA integrity and alkylation is associated with semen quality and assisted reproduction technology (ART) treatment outcomes, in particular fertilisation and cleavage rates. Male partners of couples attending for infertility treatment were recruited.

How can exposure assessment for pesticides in epidemiological studies be improved? Insights from the IMPRESS project.

The IMPRoving Exposure aSSessment Methodologies for Epidemiological Studies on Pesticides (IMPRESS) project (http://www.impress-project.org/) aimed to further the understanding of the performance of pesticide exposure assessment methods (EAMs).

Development and Application of a Slot-Blot Assay Using the Damage Sensing Protein Atl1 to Detect and Quantify -Alkylated Guanine Bases in DNA.

Humans are unavoidably exposed to numerous different mutagenic DNA alkylating agents (AAs), but their role in the initiation of cancers is uncertain, in part due to difficulties in assessing human exposure. To address this, we have developed a screening method that measures promutagenic -alkylguanines (-AlkGs) in DNA and applied it to human DNA samples. The method exploits the ability of the alkyltransferase-like protein (Atl1) to recognise and bind to a wide range of -AlkGs in DNA.

Respiratory and Other Hazard Characteristics of Substances in Cleaning Products Used in Healthcare Centres in England and Wales.

Occupational use of cleaning products can cause asthma in healthcare workers but the cleaning agents responsible are not yet known. This study aimed to identify respiratory and other hazards in cleaning products on the National Health Service (NHS) supply chain online catalogue and used in the NHS. Information on cleaning products, their composition, and H-statements that identified hazard characteristics of chemical substances in them was obtained from chemical safety data sheets (SDSs).

Inconsistent health hazard information across safety data sheets for substances in cleaning products used in healthcare centres.

Safety Data Sheets (SDSs) are used to inform downstream users of any hazardous substances in chemical products and advise on how to manage the risks from using these products. It is therefore important that information on the SDS is accurate and consistent. This study investigates the accuracy and consistency of hazard information included in the SDSs of cleaning products used in the healthcare sector in England and Wales.

Occupational exposure to pesticides and neurobehavioral outcomes. Impact of different original and recalled exposure measures on the associations.

Background: Several measures of occupational exposure to pesticides have been used to study associations between exposure to pesticides and neurobehavioral outcomes. This study assessed the impact of different exposure measures for glyphosate and mancozeb on the association with neurobehavioral outcomes based on original and recalled self-reported data with 246 smallholder farmers in Uganda.

Methods: The association between the 6 exposure measures and 6 selected neurobehavioral test scores was investigated using linear multivariable regression models.

Sixty years of research on bracken fern (Pteridium spp.) toxins: Environmental exposure, health risks and recommendations for bracken fern control.

Bracken fern (Pteridium spp.) is a highly problematic plant worldwide due to its toxicity in combination with invasive properties on former farmland, in deforested areas and on disturbed natural habitats. The carcinogenic potential of bracken ferns has caused scientific and public concern for six decades.

The application of the mobile application for the assessment of cleaning workers' exposure to cleaning products: a pilot study.

Background: Cleaning product use has been associated with adverse respiratory health effects such as asthma in cleaning staff and healthcare workers. Research in health effects from cleaning products has largely depended upon collecting exposure information by questionnaires which has limitations such as recall bias and underestimation of exposure. The aim of this study was to develop a Cleaning and Hazardous Products Exposure Logging (CHaPEL) app with a barcode scanner and to test the feasibility of this app with university cleaners.

Self-reported and urinary biomarker-based measures of exposure to glyphosate and mancozeb and sleep problems among smallholder farmers in Uganda.

Objective: We aim to showcase the impact of applying eight different self-reported and urinary biomarker-based exposure measures for glyphosate and mancozeb on the association with sleep problems in a study among 253 smallholder farmers in Uganda.

Methods: The questionnaire-based exposure measures included: (1) the number of application days of any pesticide in the last 7 days (never, 1-2; >2 days) and six glyphosate and mancozeb-specific measures: (2) application status over the last 12 months (yes/no), (3) recent application status (never, last 7 days and last 12 months), (4) the number of application days last 12 months, (5) average exposure-intensity scores (EIS) and (6) EIS-weighted number of application days in last 12 months. Based on 384 repeated urinary biomarker concentrations of ethylene thiourea (ETU) and glyphosate from 84 farmers, we also estimated (7) average biomarker concentrations for all 253 farmers.

Factors influencing occupational exposure to pyrethroids and glyphosate: An analysis of urinary biomarkers in Malaysia, Uganda and the United Kingdom.

Background: Long-term exposure to pesticides is often assessed using semi-quantitative models. To improve these models, a better understanding of how occupational factors determine exposure (e.g.

Mass Spectrometric Analysis of the Active Site Tryptic Peptide of Recombinant -Methylguanine-DNA Methyltransferase Following Incubation with Human Colorectal DNA Reveals the Presence of an -Alkylguanine Adductome.

Human exposure to DNA alkylating agents is poorly characterized, partly because only a limited range of specific alkyl DNA adducts have been quantified. The human DNA repair protein, -methylguanine -methyltransferase (MGMT), irreversibly transfers the alkyl group from DNA -alkylguanines (-alkGs) to an acceptor cysteine, allowing the simultaneous detection of multiple -alkG modifications in DNA by mass spectrometric analysis of the MGMT active site peptide (ASP). Recombinant MGMT was incubated with oligodeoxyribonucleotides (ODNs) containing different -alkGs, Temozolomide-methylated calf thymus DNA (Me-CT-DNA), or human colorectal DNA of known -MethylG (-MeG) levels.

Assessment of the association between ambient air pollution and stillbirth in the UK: Results from a secondary analysis of the MiNESS case-control study.

Objective: We examined whether the risk of stillbirth was related to ambient air pollution in a UK population.

Design: Prospective case-control study.

Setting: Forty-one maternity units in the UK.

Impact of occupational pesticide exposure assessment method on risk estimates for prostate cancer, non-Hodgkin's lymphoma and Parkinson's disease: results of three meta-analyses.

Assessment of occupational pesticide exposure in epidemiological studies of chronic diseases is challenging. Biomonitoring of current pesticide levels might not correlate with past exposure relevant to disease aetiology, and indirect methods often rely on workers' imperfect recall of exposures, or job titles. We investigated how the applied exposure assessment method influenced risk estimates for some chronic diseases.

Recall of exposure in UK farmers and pesticide applicators: trends with follow-up time.

Background: Occupational epidemiological studies on pesticide use commonly rely on self-reported questionnaire or interview data to assess exposure. Insight into recall accuracy is important, as misclassification of exposures due to imperfect recall can bias risk estimates.

Methods: We assessed the ability of workers in three UK cohorts (Prospective Investigation of Pesticide Applicators' Health [PIPAH], Pesticide Users' Health Study [PUHS], and Study of Health in Agricultural Work [SHAW]) to remember their working history related to pesticide exposure over time periods ranging from 3 to 14 years prior.

Evaluation of two-year recall of self-reported pesticide exposure among Ugandan smallholder farmers.

Objectives: To evaluate smallholder farmers' recall of pesticide use and exposure determinants over a two-year period in a low-income country context.

Methods: The Pesticide Use in Tropical Settings (PESTROP) study in Uganda consists of 302 smallholder farmers who were interviewed in 2017. In the same season in 2019, these farmers were re-questioned concerning pesticide use (e.

Insufficient respiratory hazard identification in the safety data sheets for cleaning and disinfection products used in healthcare organisations across England and Wales.

Background: Exposure to cleaning and disinfection products has been associated with respiratory disorders such as asthma in cleaning and healthcare workers. Safety data sheets (SDSs) provide information on hazardous chemicals that are present in products to help users with risk assessment and implement appropriate control measures. However, they have potential limitations in identifying respiratory hazards due to a lack of regulatory test methods for respiratory sensitisation and irritation of chemicals.

Geochemical compositional controls on DNA strand breaks induced in in vitro cell-free assays by crushed rock powders from the Panasqueira mine area, Portugal.

DNA strand breaks are a common form of DNA damage that can contribute to chromosomal instability or gene mutations. Such strand breaks may be caused by exposure to heavy metals. The aim of this study was to assess the level of DNA strand breaks caused by µm-scale solid particles of known chemical composition with elevated heavy metals/metalloids, notably arsenic, using an in vitro cell-free DNA plasmid scission assay.

Synthesis of oligodeoxyribonucleotides containing a tricyclic thio analogue of -methylguanine and their recognition by MGMT and Atl1.

Promutagenic -alkylguanine adducts in DNA are repaired in humans by -methylguanine-DNA-methyltransferase (MGMT) in an irreversible reaction. Here we describe the synthesis of a phosphoramidite that allows the preparation of oligodeoxyribonucleotides (ODNs) containing a novel tricyclic thio analogue of -methylguanine in which the third ring bridges the 6-thio group and C7 of a 7-deazapurine. These ODNs are very poor substrates for MGMT and poorly recognised by the alkyltransferase-like protein, Atl1.

Improving Exposure Assessment Methodologies for Epidemiological Studies on Pesticides: Study Protocol.

Background: Exposure to certain pesticides has been associated with several chronic diseases. However, to determine the role of pesticides in the causation of such diseases, an assessment of historical exposures is required. Exposure measurement data are rarely available; therefore, assessment of historical exposures is frequently based on surrogate self-reported information, which has inherent limitations.

Evaluation of proteins in natural rubber latex gloves and pulmonary function amongst female nurses in two tertiary hospitals in southern, Thailand.

Background: Inhaled natural rubber latex (NRL) allergens in a healthcare environment can cause NRL sensitization and reduce pulmonary functions.

Objectives: To determine the amount of proteins and the effects of NRL gloves on the pulmonary functions of female nurses in two hospitals in the southern Thailand.

Methods: The study included 340 female nurses from two hospitals in which self-reported information and a blood sample were collected.

Biomarkers of exposure in environment-wide association studies - Opportunities to decode the exposome using human biomonitoring data.

Background: The European Union's 7th Framework Programme (EU's FP7) project HEALS - Health and Environment-wide Associations based on Large Population Surveys - aims a refinement of the methodology to elucidate the human exposome. Human biomonitoring (HBM) provides a valuable tool for understanding the magnitude of human exposure from all pathways and sources. However, availability of specific biomarkers of exposure (BoE) is limited.

Silver nanoparticles exhibit size-dependent differential toxicity and induce expression of syncytin-1 in FA-AML1 and MOLT-4 leukaemia cell lines.

Human endogenous retrovirus (HERV) sequences make up ~8% of the human genome and increased expression of some HERV proteins has been observed in various pathologies including leukaemia and multiple sclerosis. However, little is known about the function of these HERV proteins or environmental factors which regulate their expression. Silver nanoparticles (AgNPs) are used very extensively as antimicrobials and antivirals in numerous consumer products although their effect on the expression of HERV gene products is unknown.

Cytotoxicity and genotoxicity of urban particulate matter in mammalian cells.

Ambient air particulate matter (PM)-associated reactive oxygen species (ROS) have been linked to a variety of altered cellular outcomes. In this study, three different PM samples from diesel exhaust particles (DEPs), urban dust standard reference material SRM1649a and air collected in Manchester have been tested for their ability to oxidise DNA in a cell-free assay, to increase intracellular ROS levels and to induce CYP1A1 gene expression in mammalian cells. In addition, the cytotoxicity and genotoxicity of PM were assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and alkaline comet assay, respectively.