Work-related ill-health: Republic of Ireland, Northern Ireland, Great Britain 2005-2012

Exposure to Inhalable Dust, Endotoxin, and Total Volatile Organic Carbons on Dairy Farms Using Manual and Automated Feeding Systems

Introduction

Agricultural workers tend to have high exposures to organic dusts which may induce or exacerbate respiratory disorders. Studies investigating the effect of work tasks and farm characteristics on organic dust exposures among farm workers suggest that handling of animal feed is an important exposure determinant; however, the effect of the animal feeding system has not been explored in any detail.

Objectives

To measure the exposure of Irish dairy farmers to inhalable dust, endotoxin, and total volatile organic compounds (TVOCs) during parlour work and to explore whether levels of exposure to these agents depend on the applied feeding system in the farms.

Methods

Thirty-eight personal exposure measurements were collected from farmers across seven dairy farms. The farms used manual, loft, or semi-automated feeding systems. Information on worker tasks and farm characteristics was collected during the surveys. Associations between exposure concentrations and feeding systems, worker tasks, and other farm characteristics were explored in linear mixed-effect regression models with farmer identity treated as a random effect.

Results

Exposure concentrations were variable and had a geometric mean (GM; geometric standard deviation) of 1.5 mg m-3 (1.8) for inhalable dust and 128 EU m-3 (2.5) for endotoxin. More than 50% of the exposure measurements for endotoxin, and organic dust exceeded recommended health-based occupational exposure limits. Endotoxin levels were somewhat lower in farms using semi-automatic feeding systems when compared to those using manual feeding systems but in multivariate regression analysis associations were not statistically significant (β = -0.54, P = 0.4). Performance of activities related to handling and spreading of hay or straw was the strongest determinant for both inhalable dust and endotoxin exposure (β = 0.78, P ≤ 0.001; β = 0.72, P = 0.02, respectively). The level of dust exposure increased also as a consequence of a lower outdoor temperature, and higher ratio of distributed feed per cow (P = 0.01). Stationary measurements of TVOC and CO2 concentrations inside the dairy parlours had a GM of 180 ppb (1.9) and 589 ppb (1.3), respectively. The use of cow teat disinfectants and building ventilation were both strong predictors of TVOC concentrations within parlours.

Conclusions

Dairy farm workers can be exposed to high and variable levels of inhalable dust and endotoxin and may be at risk of respiratory disease. Results from this study suggest that exposure control strategies for organic dusts and TVOCs exposures should consider building ventilation and work tasks such as spreading of bedding material, using spray disinfectants and animal feeding. Until effective permanent engineering controls are established farm workers should be encouraged to wear respiratory protective equipment during these tasks.

The Health and Occupation Research Network: An Evolving Surveillance System

Vital to the prevention of work-related ill-health (WRIH) is the availability of good quality data regarding WRIH burden and risks. Physician-based surveillance systems such as The Health and Occupation Research (THOR) network in the UK are often established in response to limitations of statutory, compensation-based systems for addressing certain epidemiological aspects of disease surveillance. However, to fulfil their purpose, THOR and others need to have methodologic rigor in capturing and ascertaining cases. This article describes how data collected by THOR and analogous systems can inform WRIH incidence, trends, and other determinants. An overview of the different strands of THOR research is provided, including methodologic advancements facilitated by increased data quantity/quality over time and the value of the research outputs for informing Government and other policy makers. In doing so, the utility of data collected by systems such as THOR to address a wide range of research questions, both in relation to WRIH and to wider issues of public and social health, is demonstrated.

Occupational lung disease survey of respiratory physicians in Northern Ireland

BACKGROUND

Respiratory physicians are likely to encounter occupational lung disease (OLD) in their daily practice.

AIMS

To assess the profile of cases being encountered by general respiratory physicians in Northern Ireland (NI) and determine satisfaction with training, confidence in diagnosis and management of OLD.

METHODS

An online survey of all consultant respiratory physicians currently practising in NI. Questions assessed the numbers of new cases seen over the preceding year, case type, satisfaction with specialist registrar training in OLD and degree of confidence in the diagnosis and management of these conditions.

RESULTS

Of the 40 consultants identified, the response rate was 80% (n = 32) with 94% of respondents (n = 30) indicating they had dealt with patients suspected of having occupation-related respiratory symptoms. The most commonly encountered OLDs were pleural plaques (91% of respondents), occupational asthma (88%), asbestosis (84%), non-asbestosis pulmonary fibrosis (76%), hypersensitivity pneumonitis (67%) and mesothelioma (66%). Just over one third of consultants (36%, n = 10) indicated a lack of confidence in diagnosis and management of OLD with almost half (48%) dissatisfied with OLD training as a registrar and a further 78% (n = 25) indicating they would value additional training in OLD as a consultant.

CONCLUSIONS

The majority of respiratory consultants in NI encountered OLD in their day to day practice and half were dissatisfied with their specialist registrar training in OLD and express a lack of confidence in the diagnosis and management of these conditions. This highlights the need for additional training at both registrar and consultant level.