Conjunctivitis is an inflammation of the conjunctiva characterized by swelling, redness, discharge, and discomfort. It is a common diagnosis in the general population (Azari and Barney, 2013) and the most common ocular condition diagnosed in United States’ emergency rooms where it accounts for almost one-third of all eye-related visits (Channa et al. 2016). Conjunctivitis can be infectious (generally caused by adenovirus) or noninfectious (autoimmune, hypersensitivity, etc.).
Conjunctivitis significantly impacts health-care systems; outbreaks can cause significant morbidity, high health-care costs, and loss of workdays, which result in financial burdens on both individuals and the public worldwide (Azari and Barney, 2013; Channa, et al., 2016; Schneider et al., 2014). In the United States, 4–6 million conjunctivitis visits annually entail nearly 800 million dollars in treatment costs (Schneider et al., 2014). The direct effects of the condition on patients’ quality of life can vary, ranging from lost school/work to irreversible eye and vision damage. More information about environmental risk factors is crucial to develop measures to reduce the incidence and burden on public health of conjunctivitis (Chen et al., 2019).
Ambient temperature and air pollution are known to be associated with a variety of health problems and disorders that affect multiple body systems, such as respiratory, cardiovascular, and neurological systems (Maayan et al., 2015; Gerber et al., 2006; Anderson et al., 2013; Eccles, 2002; Alina et al., 2015; Aditi et al., 2016; Vencloviene et al., 2015; Vodonos et al., 2014; Vodonos et al., 2015; Yang et al., 2011). In severe cases, temperature and air pollution can be fatal to individuals (Jhun et al., 2017; Lelieveld, et al., 2015; Aditi et al., 2016; Jun et al., 2016). Several studies have revealed meteorological effects on the ocular system (Bourcier et al., 2003; Hu et al., 2007; Stein et al., 2011; Christoph et al., 2016; Matthew et al., 2016; Setten et al., 2016; Augera et al., 2017), but few agree about the relationship of meteorological changes with conjunctivitis (Andre et al., 2011; Chia-Jen et al., 2012; Chiang et al., 2012; Hong et al., 2016; Szyszkowicz et al., 2016).
Chia-Jen et al. (2012) reported more outpatient visits for conjunctivitis in winter than in summer; however, Chiang et al. (2012) reported that average daily visits for acute conjunctivitis peaked in the summer. According to Szyszkowicz et al. (2016), the number of visits was higher in the warm season than the cold season. Azari and Barney (2013) reported a greater incidence of viral conjunctivitis in summer and bacterial conjunctivitis from December through April. These studies all evaluated the incidence of conjunctivitis by season rather than by temperature.
The present study was undertaken to evaluate the association between air pollution, ambient temperature, and emergency room visits for conjunctivitis in the Negev Desert of southern Israel. This 13,000 km² semi-arid region lies between the Saharan and Arabian deserts and the three together constitute the world’s largest dust belt. In the light of climate change and desertification, the Negev can be considered a predictor of future climate change in many regions of Europe.