Biological monitoring of pesticide exposures in residents living near agricultural land

<p>Abstract</p> <p>Background</p> <p>There is currently a lack of reliable information on the exposures of residents and bystanders to pesticides in the UK. Previous research has shown that the methods currently used for assessing pesticide exposure for regulatory purposes are appropriate for farm workers <abbrgrp><abbr bid="B1">1</abbr></abbrgrp>. However, there were indications that the exposures of bystanders may sometimes be underestimated. The previous study did not collect data for residents. Therefore, this study aims to collect measurements to determine if the current methods and tools are appropriate for assessing pesticide exposure for residents living near agricultural fields.</p> <p>Methods/design</p> <p>The study will recruit owners of farms and orchards (hereafter both will be referred to as farms) that spray their agricultural crops with certain specified pesticides, and which have residential areas in close proximity to these fields. Recruited farms will be asked to provide details of their pesticide usage throughout the spray season. Informed consenting residents (adults (18 years and over) and children(aged 4-12 years)) will be asked to provide urine samples and accompanying activity diaries during the spraying season and in additionfor a limited number of weeks before/after the spray season to allow background pesticide metabolite levels to be determined. Selected urine samples will be analysed for the pesticide metabolites of interest. Statistical analysis and mathematical modelling will use the laboratory results, along with the additional data collected from the farmers and residents, to determine systemic exposure levels amongst residents. Surveys will be carried out in selected areas of the United Kingdom over two years (2011 and 2012), covering two spraying seasons and the time between the spraying seasons.</p> <p>Discussion</p> <p>The described study protocol was implemented for the sample and data collection procedures carried out in 2011. Based on experience to date, no major changes to the protocol are anticipated for the 2012 spray season although the pesticides and regional areas for inclusion in 2012 are still to be confirmed.</p

Occupational dermal exposure to nanoparticles and nano-enabled products:Part I − Factors affecting skin absorption

The paper reviews and critically assesses the evidence on the relevance of various skin uptake pathways for engineered nanoparticles, nano-objects, their agglomerates and aggregates (NOAA). It focuses especially in occupational settings, in the context of nanotoxicology, risk assessment, occupational medicine, medical/epidemiological surveillance efforts, and the development of relevant exposure assessment strategies. Skin uptake of nanoparticles is presented in the context of local and systemic health effects, especially contact dermatitis, skin barrier integrity, physico-chemical properties of NOAA, and predisposing risk factors, such as stratum corneum disruption due to occupational co-exposure to chemicals, and the presence of occupational skin diseases. Attention should be given to: (1) Metal NOAA, since the potential release of ions may induce local skin effects (e.g. irritation and contact dermatitis) and absorption of toxic or sensitizing metals; (2) NOAA with metal catalytic residue, since potential release of ions may also induce local skin effects and absorption of toxic metals; (3) rigid NOAA smaller than 45nm that can penetrate and permeate the skin; (4) non rigid or flexible NOAA, where due to their flexibility liposomes and micelles can penetrate and permeate the intact skin; (5) impaired skin condition of exposed workers. Furthermore, we outline possible situations where health surveillance could be appropriate where there is NOAA occupational skin exposures, e.g. when working with nanoparticles made of sensitizer metals, NOAA containing sensitizer impurities, and/or in occupations with a high prevalence of disrupted skin barrier integrity. The paper furthermore recommends a stepwise approach to evaluate risk related to NOAA to be applied in occupational exposure and risk assessment, and discusses implications related to health surveillance, labelling, and risk communication

Trends in wood dust inhalation exposure in the UK, 1985-2005

OBJECTIVES: Wood dust data held in the Health and Safety Executive (HSE) National Exposure DataBase (NEDB) were reviewed to investigate the long-term changes in inhalation exposure from 1985 to 2005. In addition, follow-up sampling measurements were obtained from selected companies where exposure measurements had been collected prior to 1994, thereby providing a follow-up period of at least 10 years, to determine whether changes in exposure levels had occurred, with key staff being interviewed to identify factors that might be responsible for any changes observed. METHODS: Analysis of the temporal trend in exposure concentrations was performed using Linear Mixed Effect Models on the log-transformed NEDB data set and expressed as the relative annual change in concentration. RESULTS: For the NEDB wood dust data, an annual decline of geometric mean (GM) exposure of 8.1% per year was found based on 1459 exposure measurements collected between 1985 and 2003. This trend was predominantly observed in data from inspection visits (measurements collected on a mandatory basis by a Specialist HSE Inspector) (n = 1009), while data from representative surveys (measurements collected on a voluntary basis to provide information on current practices and exposures) remained relatively stable. Ten follow-up surveys in individual workplaces in 2004-2005 resulted in 70 new measurements and for each of the companies resurveyed, the GM of the wood dust exposure decreased between sampling surveys. CONCLUSION: Analysis of the temporal trend in UK wood dust exposure concentrations revealed declines of 8% per annum. Interviews with key long-serving employees and management suggest that factors such as technological changes in production processes, response to new legislation, and enforcement agency inspections, together with global economic trends, could be linked to the downward trends observed