Respiratory health of road-side vendors in a large industrialized city

Abstract

Goal, Scope and Background

The literature reports a high prevalence of respiratory symptoms associated with exposure to motor vehicle exhaust emissions and people exposed to vehicle emissions are at risk of reduced lung function and cardiovascular performance. Although the effect of traffic emissions is a known risk to respiratory health, retailers are often situated along major roads in a busy urban environment to maximise customers. Shop assistants in an air-conditioned environment should be less exposed to traffic fumes and their lung function should be better preserved compared to ‘unprotected’ vendors exposed directly to vehicle emissions. The lung function of these two groups of workers has not previously been compared. The aims of this study are to determine if there is a difference in the concentration of respirable particles of diameter less than 10 micrometers (PM₁₀) inside and outside air-conditioned shops along a busy major road; and to compare the lung function parameters, blood lead levels and respiratory symptoms between road-side vendors directly ‘exposed’ to traffic fumes and vendors working in ‘protected’ air-conditioned shops along the same road.

Methods

Roadside vendors (n=33) and adjacent shop assistants (n=31) were recruited for the study in a district known to have high emissions and pollution measures. All subjects were asked to complete a questionnaire providing the frequency of their respiratory symptoms. Spirometry pulmonary function tests were conducted and exhaled carbon monoxide levels (E_CO), oxygen saturation and blood lead levels (BLL) were measured. PM₁₀ level was concurrently measured in the subject’s working environment. Pulmonary function data and E_CO levels collected from a cohort of university staff aged ≥ 30 years (n=92) at a university campus were included for comparison.

Results

The concentration of particulate matter (PM₁₀) at the roadside (210 ± 70 μg/m³) was significantly higher than inside the shops (130 ± 40 μg/m³). There was no difference in lung function parameters or BLL between the groups, however the forced vital capacity of both groups of vendors was significantly lower than a ‘control’ cohort of academic institution personnel (n=92).

Discussion

This study illustrated that while the level of pollution improved with air conditioning, this may not be sufficient to prevent respiratory consequences. Our data suggests that a reduction in occupational exposure is not enough to protect these workers.

Conclusions

Air-conditioned work environment is insufficient to protect the respiratory system against the adverse effects of exposure to vehicle emissions.

Recommendations

The overwhelming effect of exposure during travel to and from work and at home cannot be underestimated. More stringent guidelines to control pollution appear necessary to protect the respiratory health of both shop-keepers and roadside vendors and further studies to explore the effect on respiratory health of the exposure to pollutants associated with commuting to and from work are warranted.