Noise sensitivity: Symptoms, health status, illness behavior and co-occurring environmental sensitivities

Highlights

• People with self-reported noise sensitivity experience multiple non-specific symptoms.

• They also report comparatively poorer health and increased illness behavior.

• Co-occurrence with other environmental sensitivities is moderate to high.

• Road-traffic noise and GP-registered morbidity did not account for these results.

Abstract

Epidemiological evidence on the symptomatic profile, health status and illness behavior of people with subjective sensitivity to noise is still scarce. Also, it is unknown to what extent noise sensitivity co-occurs with other environmental sensitivities such as multi-chemical sensitivity and sensitivity to electromagnetic fields (EMF). A cross-sectional study performed in the Netherlands, combining self-administered questionnaires and electronic medical records of non-specific symptoms (NSS) registered by general practitioners (GP) allowed us to explore this further. The study sample consisted of 5806 participants, drawn from 21 general practices. Among participants, 722 (12.5%) responded “absolutely agree” to the statement “I am sensitive to noise”, comprising the high noise-sensitive (HNS) group. Compared to the rest of the sample, people in the HNS group reported significantly higher scores on number and duration of self-reported NSS, increased psychological distress, decreased sleep quality and general health, more negative symptom perceptions and higher prevalence of healthcare contacts, GP-registered NSS and prescriptions for antidepressants and benzodiazepines. These results remained robust after adjustment for demographic, residential and lifestyle characteristics, objectively measured nocturnal noise exposure from road-traffic and GP-registered morbidity. Co-occurrence rates with other environmental sensitivities varied between 9% and 50%. Individuals with self-declared sensitivity to noise are characterized by high prevalence of multiple NSS, poorer health status and increased illness behavior independently of noise exposure levels. Findings support the notion that different types of environmental sensitivities partly overlap.

Introduction

Noise sensitivity refers to the internal states of any individual which increase their degree of reactivity to noise in general (Job, 1999) through pathways related to physiological, psychological, including attitudinal characteristics or pathways related to life style or activity patterns. There are a number of competing and complementary hypotheses regarding the etiology of noise sensitivity and its potential role (van Kamp et al., 2013): It could be a result of physical illness, injury, psychological disorder, a partial indicator of genetically related vulnerability or acquired vulnerability to environmental stressors, or even a side-effect of prescribed medication (van Kamp and Davies, 2013). Noise sensitivity might directly influence health or moderate the relationship between noise and well-being (Stansfeld, 1992, Heinonen-Guzejev et al., 2007; Fyhri et al., 2009; Kishikawa et al., 2009). It has been linked to poor perceived health and increased psychological distress, morbidity, medication use and risk of disability pension (Stansfeld et al., 1993, Heinonen-Guzejev et al., 2004, Heinonen-Guzejev et al., 2013, Stansfeld and Shipley, 2015). There is also the notion that noise sensitivity could be part of the broader spectrum of subjective environmental sensitivities attributed to low, compared to the established safety limits, exposure levels to environmental agents such as chemicals and electromagnetic fields (EMF) (Nordin et al., 2013, Palmquist et al., 2014).

People with these environmental sensitivities are often characterized by increased report of non-specific symptoms (NSS) (Das-Munshi et al., 2006, Staudenmayer et al., 2003). Such symptoms occur in various organ systems and can be caused by multiple factors, often unknown and unrelated to the attributed (environmental) cause. When presented in primary care, between 30% and 50% of NSS cannot be explained by a medical diagnosis (Kroenke and Price, 1993, Barsky and Borus, 1999). The term “medically unexplained” is often used to describe such complaints in clinical practice (Henningsen et al., 2011). Decreased physical functioning, increased illness behavior (particularly related to alternative therapies) and negative symptom perceptions have also been observed in some environmentally sensitive groups (Baliatsas et al., 2014).

However, it is not clear yet whether these features are also common in people with noise sensitivity. Noise-sensitive groups have been understudied, are generally underrepresented in study populations and evidence on differential characteristics is scarce (van Kamp and Davies, 2013), since there is limited research on their symptomatic profile, psychological relevant characteristics and co-occurrence with other environmental sensitivities. The present study addresses three main questions: (1) Do people with self-reported noise sensitivity experience more symptoms and symptoms of longer duration compared to the broader population? (2) Do noise-sensitive individuals differ from the broader population in terms of symptom report, symptom perceptions, health status indicators and illness behavior? (3) To what extent do noise- sensitive people report other environmental sensitivities as well?