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Safeguard OSH Solutions - Thomson Reuters

Safeguard OSH Solutions - Thomson Reuters

Safeguard Magazine

It’s Academic—Noise strategies

Dr IAN LAIRD summarises a recent New Zealand study on noise exposure that may make us think twice about effective noise management.

The objective of the project (funded through the HRC, ACC and Department of Labour) was to evaluate the effectiveness of existing work-related strategies to reduce NIHL in New Zealand.

Some 33 primarily small business workplaces were surveyed. The results showed that, in general, noise sources and paths could be readily identified and that area and personal sound level exposure measurements varied considerably between the high, moderate and low risk industry sectors.

It was found that of the high risk industry sectors surveyed (agriculture, manufacturing, construction), most had mean sound levels that were at or above LAeq.8hr 85dB. Mean noise exposures recorded in moderate and low risk industry sectors (cafes and preschools) were below LAeq.8hr 80dB.

The predominant noise control strategy used by the surveyed businesses was personal hearing protection. Although many operations were complex, it was found that noise management strategies aimed at the noise source and noise paths could have been investigated further.

In agriculture and construction however, prevention through noise reduction at source or isolation of the noise, even though best practice, may not always be practicable; so that hearing protection could be the only control option available.

Of concern, however, was the finding that most enterprises surveyed did not conform to the specific requirements of legislative standards for noise management. Conformance values – scored from the Approved Code of Practice for the Management of Noise in Workplaces – varied across all sectors and ranged from 0 to 6 out of 10, where 10 is total conformance to the CoP. The mean value was 2.0, with a standard deviation of 1.7.

Of the high risk sectors surveyed, manufacturing and farming were the most compliant sectors, but still relatively low (mean conformance scores of 4.3 and 3.0 respectively). Mean conformance scores for the remaining industry sectors ranged from 2.3 down to 0.33 out of 10.

In addition, a survey of 163 workers from these enterprises also provided information on hearing protection use, safety climate and attitudes to noise at work. The study found there was little evidence that safety climate was related to effective noise management activities. However, perceptions of safety as a personal responsibility did predict hearing protection use. The results suggest that attempts to address safety climate by changing attitudes, beliefs and perceptions may be less effective than changing unsafe conditions and behaviours at all organisational levels.

Evidence from this study suggests that an employee’s sense of personal responsibility for safety is the main motivator for protective behaviour in the workplaces surveyed, rather than management initiatives or leadership.

After decades of effort in trying to promote and improve health and safety management at the organisational level, this is disappointing. It is concluded that noise hazards are best managed directly rather than indirectly through attempts to change climate through marketing, training or attitude change. Safety climate is complicated. Different facets have different correlates and implications. The findings from this study suggest that perceptions of safety climate may follow, rather than lead, safety management efforts in relation to noise control within the businesses.

So what needs to be done? A range of strategies have been proposed. They include:

  • • 
    establishing noise exposure and NIHL as national health and safety priorities;
  • • 
    relate community (leisure and home) intervention strategies with workplace initiatives;
  • • 
    the Prevention through Design (PtD) initiative developed by NIOSH (2010) could be successfully applied to reduce the noise exposure of equipment and machinery used in high risk industry sectors;
  • • 
    changes in expectations with respect to policing the requirements of noise regulations;
  • • 
    increased enforcement activity from the DoL is seen as an important part of a multilevel national strategy for the prevention of NIHL;
  • • 
    the potential for introducing into New Zealand legislation a strata of action levels (lower and upper) similar to those recently introduced in Europe and the UK could be investigated to reinforce the current NZ standards;
  • • 
    adoption of “best” or “good” practice models for noise control, including noise control measures that actually improve productivity and reduce costs;
  • • 
    development and maintenance of surveillance schemes for occupational hearing loss and surveillance of workplace noise exposure;
  • • 
    adoption of interventions designed for small businesses within the high risk sectors (agriculture, construction and manufacturing) identified in this report, as over 90% of these enterprises have fewer than 20 employees;
  • • 
    initiatives providing technical advice and support for enterprises have been developed and trialled in Australia, UK and Europe with varying levels of success.

Interventions need to be cyclical, on-going and evaluated (Laird, et al., 2010). Above all, we need to set out a vision for the prevention of hearing loss in New Zealand where “hearing is regarded as a special sense that is valued by the community in home, work and leisure environments”.

Dr Ian Laird is an associate professor in occupational health and safety in the Centre for Ergonomics, Occupational Safety and Health, Massey University, Palmerston North.

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