Does smog affect the incidence of exacerbations of chronic laryngitis? Analysis based on the inhabitants of Lesser Poland Voivodeship

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Does smog affect the incidence

of exacerbations of chronic laryngitis?

Analysis based on the inhabitants of Lesser Poland Voivodeship

Remigiusz Ziarno

¹

, Anna Suska

¹

, Wojciech Kulinowski

²

, Aleksandra Grudzień-Ziarno

³

, Magdalena Kostrzon

⁴

, Magdalena Paciorek

⁴

, Jacek Składzień

³

1Students Scientific Group at the Otolaryngologic Clinic Collegium Medicum, Jagiellonian University

2Pedagogical University of Cracow

3Clinical Department of Otolaryngology, University Hospital, Cracow

4Salt Mine „Wieliczka”

Article history: Received: 14.03.2017 Accepted: 02.04.2017 Published: 15.06.2017

ABSTRACT: Introduction: Due to dynamic industrialisation smog became a frequent phenomenon in most developing cities. Ac- cording to the last WHO report from Global Urban Ambient Air Pollution Database, Krakow has been classified in the 11th place among the most polluted cities in Europe. It seems to be an urgent issue because of the influence of air pollution on the condition of upper respiratory tract.

Materials & Methods: In December 2015 there were 141 patients aged 17-91 years with upper respiratory tract dise- ases admitted to the phoniatric outpatient clinic in the University Hospital in Cracow. They suffered from cough, hoarseness and periodic aphonia. On the basis of the results of videolaryngostroboscopy 60 patients with exacerbation of the chronic laryngitis were selected into two numerically equal groups: from Cracow and from other places at least 60 km away. The groups were equal to each other also in three categories: sex, age and voice usage. The patients were referred to the Pedagogical University in Cracow for laryngography to evaluate the movement of the vocal folds and to trace a voice profile. Finally, there were two possible types of treatment – conventional pharmacotherapy or subterraneotherapy in the underground Health Resort in the “Wieliczka” Salt Mine.

Results: Pearson correlation coefficient between the distance from the place of residence to Cracow and the scale of exacer- bation of inflammation of upper respiratory tract presenting as vocal fold dysfunction was observed (r= 0,617; p<0,05).

Conclusion: The place of residence (in or out of the industrial area) and exacerbations of chronic laryngitis are highly correlated. Air pollution seems to be the main factor influencing on the condition of upper respiratory tract. In our local conditions of Lesser Poland Voivodeship subterraneotherapy may be an interesting, non-invasive method preven- ting from exacerbations of upper respiratory tract diseases.

KEYWORDS: air pollution, chronic laryngitis, phoniatrics, laryngography, subterraneotherapy

INTRODUCTION

Both the 20th and 21st century have been a time of rapid civi- lization progress that has begun at the end of the 19th century by the so called “industrial revolution”. This period was char- acterized by creation of large factories on an unprecedented scale and migration of people from rural areas into the cities.

Air pollution was a byproduct of this process. Initially, this

pollution that was caused by utilization of coal in the factories of Great Britain, Germany and United States was a local issue whereas, after World War 2 many new environmental threads emerged, this time of global range, including acid rains, smog, destruction of the ozone layer and climate changes. The modern urban industry, based on the burning of biomass fuels and fossil fuels, significantly widened the scale and extent of air pollution [1].

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Air pollution is a heterogeneous mixture of gases, liquids and solid particles [2, 3, 4]. Smog is an atmospheric phenomenon of limited visibility caused by a high concentration of dust and aerosol [4, 5]. Suspended dust (particulate matter; PM) is the main component of air pollution tested for negative effect on health [6]. It is estimated that every 100 μG of dust suspended in 1 m³ shortens the life expectancy by 3 years [7]. Dusts are character- ized by complex physical and chemical parameters [8]. Harm- fulness of dusts depends on the size of the particles, their mor- phology, surface characteristics and composition [6]. Organic compounds - including aromatic carbohydrates, heavy metals or gases attach to the surface of dust, increasing its toxicity [6, 9]. From a practical point of view, the classification of particles on the basis of size and diameter is most important: thick dust (2.5-10 μm) - PM10, fine dust (0.1-2.5 μM) - PM2.5 and ultrafine dust <0.1 μm) [2, 3]. Exposure to air pollution mainly results in certain conditions of the respiratory system and exacerbation of symptoms associated with the respiratory tract [10, 11, 12, 13, 14, 15, 16, 17, 18,19, 20, 21]. Thick dust (PM10) settles mainly in large airways [2, 3]. Whereas, fine dust (PM2.5) can penetrate deeply into the lungs, irritating and damaging the wall of the lung alveoli [2, 4, 5]. Research conducted at the beginning of 21st century [22, 23] indicates that exposure to the dust of this parti- cle size has serious health effects and is the leading cause of premature death around the world. The risk group includes people already suffering from respiratory diseases [8. 24, 25], children [21 26, 27, 28] and the elderly [28, 29]. The negative impact of air pollution on health is already evident at a very low exposure, so it is difficult to determine, whether there is a threshold for the concentration of particulates below which it is not harmful [2]. It was also unequivocally stated that cumulative exposure has a greater effect on mortality than transient and short-term exposure. According to WHO guidelines (Air Quality Guide- lines) the average daily concentration of PM10 should not ex- ceed 50 μg / m³. PM2.5 - 25 μg / m³, whereas an average annual concentration threshold amounts to 20 μg / m³ and 10 μg / m³ respectively [30]. In compliance with the directive of the Euro Parliament and the Council of Europe (2008/50 / EC) [31] the permissible PM10 level amounts 40 μg / m³in a year and 50 μg / m³ in 24 hours (limit may be exceeded only 35 times during a year). For the PM2.5 dust, the permissible daily level was gradually lowered, reaching zero in 2015 (average annual concentration amounts to 25 μg / m³) [31].

In 2016, WHO published a report on air quality based on the analysis of PM2.5 as the pollutant that is most hazardous to health [7]. The report includes more than 3000 cities from 103 countries around the globe. The results of the analysis are appall- ing - the air in most of the cities (above 80%) exceeds accepted standards. Furthermore, within last 5 years pollution increased by 8%. Among the 50 most polluted cities of the European Un-

ion, 33 are in Poland, mostly in the Silesia and Lesser Poland voivodship. Krakow, which was rated 11 in this score, was the only one to implement regulations on prevention of smog.

In the last decades, industrial pollution has been significantly reduced. Currently, the main causes of air pollution in developed countries include increased traffic and emission of auto- motive exhaust [12, 21]. The highest concentrations of dust are recorded near large urban arteries [26, 29. 32]. According to an American study, PM2.5 dust originated mostly from burning fuel of motor vehicles. Moreover, in Europe, car exhaust fumes also contribute to over 50% of general PM10 concentration [33]. Also in Poland, as a result of the socioeconomic transformation, the profile of anthropogenic pollutants has changed over the last few decades - nowadays emissions from motor vehicles are the main source of suspended particulate matter and the traditional emissions (industrial and municipal) contribute mostly to the increase of aerosol concentration [6].

Steadily increasing traffic is a growing threat to health [32. 34].

Most of the studies on the influence of air pollution on peo- ples’ health focuses on correlation between the concentration of the individual components of air pollution and the conditions of the lower respiratory tract. This study aims to evaluate the relationships between the level of pollution and exacerbations of upper respiratory tract diseases based on patients of the Clinical Department of Otolaryngology Clinic of the Uni- versity Hospital in Cracow, suffering from chronic laryngitis, taking into account also the place of their residence in relation to the center of Cracow.

AIR CONDITION IN LESSER POLAND VOIVODESHIP

According to the report of the Voivodship Inspectorate for Environmental Protection of 2015 [35], the highest average annual concentrations of PM10 in Lesser Poland Voivodeship (Fig.1) is being recorded in Cracow and nearby towns, whereas the lowest in the remote cities , at a distance of at least 50 km away from Cracow (including Tarnow, Zakopane, Gorlice, Limanowa, Chrzanów). The highest annual average concentrations of PM2.5 (Fig.2) are also observed in the district of Cra- cow, and the lowest in the districts: Tarnówski, Dąbrowski , Tatrzaskiand Chrzanowski.

Data of the Chief Inspectorate for Environmental Protection [36] from December 2015 correspond with the aforemen- tioned conclusions. During the whole month PM10 levels were much higher in Cracow (Fig.3) than in Tarnów (Fig. 4) and Gorlice (Fig. 5).

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MATERIAL AND METHODS

The study was conducted in cooperation with the Pedagogi- cal University of Krakow and the Salt Mine “Wieliczka”. The study protocol consisted of 3 stages. The first stage was conducted in December, 2015 at the Department of Otolaryngol- ogy, University Hospital. A total of 141 patients with upper respiratory tract complaints were registered within one month at the Phoniatrics Clinic aging between 17 and 91 years. Each patient underwent the following laryngological tests: subjec- tive rating of voice quality, maximal phonation time(MPT), laryngoscopy, and videolaryngostroboscopy. Then, 60 people of all admitted patients with exacerbation of chronic laryngitis were deliberately enrolled into the study. These patients reported mainly unproductive cough, hoarseness and periodic aphonia. These people were divided into 2 groups- the patients from Cracow and ones from outside of Cracow (60 km away from Cracow). Groups were equal in terms of number, sex, age and professional vocal effort (Tab. I). Each group consisted of 15 women and 15 men; 10 people aged 25-35 years, 10 people aged 35-45 and 10 were over the age of 45; 10 people, who use their voice professionally, and 20 who were not subjected to excessive voice effort.

After visiting the Phoniatric Out-patient Clinic, patients were referred to the Pedagogical University where the sec- ond stage of the study, laryngographic examination, was conducted. Laryngography is an improved method of electroglotography, where two electrodes are horizontally placed at the level of the larynx [37]. The electrical impedance changes among others during the movement of vocal folds. When the folds are contracted the impedance is lower than when they are open. During the analysis, the patient is asked to pro- nounce the vowels (a, o, u, e), the words (ala. ola, ula, ela) and sentences: Today is nice weather. This brave soldier was with them. During phonation, the movement of the vocal tract, especially the larynx, is visualized and quantitatively analyzed, which is presented a diagram of voice profile. As a result a histogram CFx is formed in 2D format. Based on this data, the irregularity coefficient (IC) is calculated with the use of a computer. This factor is estimated after selection of three con- secutive elements on the diagonal histogram CFx, which rep- resent regular phonation (the largest element of the matrix is selected as the middle element). It constitutes the percentage of irregular vibration of vocal folds in a registered phonation recording [37]. The closer the points are on the diagram, and the lower the IC value, the better the result is. Values of IC are considered normal, when they are lower than 10% (Fig. 6).

A high irregularity coefficient corresponds with inflammatory changes in the vocal tract (Fig. 7). Obtained results of laryngographic examination were statistically analyzed with Statistica

StatSoft. An analysis of Pearson’s correlation was conducted with the statistical significance level of 0.05.

The third stage of the study encompassed implementation of the treatment aiming at prevention of exacerbations of chronic laryngitis. Each enrolled patient had the opportunity to use subterraneotherapy in the health resort at the “Wieliczka” Salt Fig. 1. PM10 Concentration - Annual Report. Source: Assessment of air’s quality

in the Lesser Poland voivodship in 2015. - Voivodship Inspectorate for Environmental Protection in Cracow.

Fig. 2. Concentration PM 2.5 - Annual Report. Source: Assessment of Air Quality in the Lesser Poland Voivodeship in 2015. - Voivodeship Inspectorate for Environmental Protection in Cracow.

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izing ideas of clean production and environment-friendly vehicles. However, one must be aware of the fact that improving the quality of atmospheric air is a long-term process therefore, it is also important to take actions aiming at reducing exposure Mine. The turnus included 5-hour therapeutic sessions taking

place in the natural environment of the underground salt chambers, every day from Monday to Friday for 3 weeks. A single session included inhalation, exercises adjusted to the individual physical performance, respiratory exercises, and position drain- age led by specialists in physiotherapy. Within 6 weeks after completion of the rehabilitation turnnus the patients reported for a follow-up visit to the Department of Otolaryngology, University Hospital in Cracow and the Pedagogical University in order to verify effectiveness of treatment. In patients who did not want to undergo subterraneotherapy or in to whom this form of therapy was not recommended received pharma- cological treatment including supplementation of vitamins A and E, lozenges with hyaluronic acid, preparation of colloidal silver and marshmallow syrup. This group also reported for a scheduled follow-up.

RESULTS

There is a much higher number of patients with upper respiratory symptoms reporting to the Outpatient Clinic Phoniatrics of Otolaryngology, University Hospital in Cracow in autumn and winter compared to other seasons. There is a statistically significant relationship between distance of residence in relation to the center of Cracow and degree of dysfunction of the larynx presented as irregular vibration of vocal folds (strong positive correlation r =0.6170; p = 0.01).

DISCUSSION

Scientific research reveals the mechanisms of action of air pollution on the human body. During exposure, destruction and dysfunction of the lung epithelium of the respiratory tract results in impairment of mucosal ciliary transport [4, 5, 11], increased release of cytotoxic inflammatory mediators [5, 8, 38], and free radicals [4] formed as a result of oxidative stress [5, 8]. In addition, follicular macrophages are lost and phago- cytic capacity is reduced [18, 19, 38]. Exposed cells are also affected by mitochondrial changes, protein denaturation, and DNA damage [38]. Single short-term exposure to suspended dust results in impairment of the respiratory epithelial defense mechanisms, making it more prone to damage as a result of subsequent exposure. This way it increases the risk of infection [4, 8, 11. 20, 39].

Due to the need for reduction of air pollution, it is necessary to implement appropriate legislation - both on a global, and local level [9]. It is recommended to monitor pollutant emissions, industrial production, coal consumption, as well as popular-

Fig. 3. Concentration PM10 - 12.2015 Kraków, Al. Krasinskiego Source: Chief Inspectorate for Environmental Protection.

Fig. 4. Concentration PM10 - 12.2015 Tarnow, ul. Bitwy pod Studziankami.

Source: Chief Inspectorate for Environmental Protection.

Fig. 5. Concentration PM10 - 12.2015 Gorlice, ul. Krasinskiego Source: Chief Inspectorate for Environmental Protection.

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Spannagel in Germany [45, 46]. This method, once widespread in Europe, nowadays is experiencing its renaissance [46]. The resort in Salt Mine “Wieliczka” is one of the few places on the world where treatment is carried out in natural underground saline excavations. Outside of Poland this therapeutic method is used in Germany, Austria, Romania, the Czech Republic and Slovakia [45, 46]. The natural underground microclimate is beneficial for patients with chronic respiratory diseases [49]

especially in recurrent upper and lower respiratory tract infections, chronic non-allergic rhinitis, allergic rhinitis, chronic pharyngitis, chronic laryngitis, chronic bronchitis, bronchi- ectasis, or pneumonia [45], as well as in asthma, COPD and in skin allergy conditions [46]. Subterraneotherapy remains a unique therapeutic method against today’s innovative advances in medicine and highly specialized pharmacotherapy because it applies primarily natural underground spaces for intensive rehabilitation, including inhalationa as well as various forms of physical activity adjusted to the performance of an individual patient [45, 46].The quality of the air in underground salt caves is a key factor determining effectiveness of this therapy [47, 50. 51, 52].

In the resort in Wieliczka, the air is purified from dust, allergens, and bacteria, has a high relative humidity (60–75%), temper- ature ranging from 12.9 to 14.5˚C, and high NaCl concentration (3,0–10,0 mg/m³). It is also enriched with elements such as: magnesium, calcium, manganese and potassium [47, 48].

Natural brine which is used for aerosol therapy comes from a water source at the Wieliczka Salt Mine on a depth of 255 and to counteract against negative effect of pollutants. China

has tried to develop a list of interventions recommended for use during smog [9]. This includes avoiding physical activity in the open air, wearing adapted protective masks, limiting the combustion of biomass fuels [39, 40. 41. 42], limiting smok- ing [44], antioxidant intake [43],as well as the use of air filters.

However, the benefits of of implementation of this method have not been proven [9].

The 21st century brings many therapeutic novelties. This century is already called “Age of Prevention “because increased public awareness of the protection of one’s own health [45]. In this context natural methods of treatment are becoming more and more widespread in various fields of medicine. Balneology and physical medicine is developing rapidly. Subterraneother- apy is a complementary method accompanying pharmacolog- ical treatment. It encompasses balneology using microclimate in underground salt chambers [45, 46, 47]. The law act on spa treatment, health resorts and health resort areas as well as the health resort districts of 28 July, 2005 regulates this form of spa treatment for the first time [46]. The beginnings of subterraneotherapy in Poland date back to the 1930s. At that time Dr. Feliks Boczkowski claimed that a prolonged stay in deep salt mine chambers is more effective than saline inhalation in treatment of respiratory tract [46, 48]. Doctor Boczkowski in- itiated foundation of the first resort in Wieliczka for patients with pulmonary conditions. Modern theoretical and practical basis of subterraneotherapy were formulated in the 1950’s by Prof. Mieczyslaw Skulimowski in Poland and Dr. Karl Hermann

Fig. 6. An example of histogram CFx of a patient outside of Cracow. C = 2.75%. Ryc. 7. An example of histogram <t0/>CFx<t1/> of a patient from Cracow. IC = 40.29%.

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vocal effort and gastroesophageal reflux [56]. Typically, the disease develops gradually. Symptoms such as hoarseness, lower- ing and weakening of the voice, and dry cough last for weeks or months. They can alternately weaken and aggravate, especially when the exposure damaging factor is being repeated [3]. A scientific study conducted in South Korea only for suspended dust PM10 (out of many analyzed air contaminants including CO, NO₂, SO₂Ozone) multivariate analysis of logistic regression revealed a correlation with the incidence of chronic laryngitis[3].

This analysis was based on a cross-sectional study. In addition, this analysis does not take into account the differences in air pollution within cities, which may be similarly significant or even more significant than differences between the cities. Unfortu- nately, most of the scientific research focused on the impact of atmospheric air quality on health, similarly to our study does not precisely define the size of exposure to pollution. Usually the researchers use the distance from busy routes or data on route traffic rates [15]. Therefore, it is difficult to estimate the threshold for individual components of pollution, above which the risk for health significantly increases.

In Cracow, measures are taken to reduce air pollution, especially during the heating season, when the highest levels of suspended particulate matter and the most frequent exacerbations of chronic respiratory diseases are recorded. The implementation of these plans requires time, while the methods for protection of the inhabitants of large industrial cities should be applied simultaneously in order to prevent the negative impact of smog on respiratory tract.

It seems that alternative methods, in our case - subterraneoterapy - can also have beneficial effects on health and condition of upper respiratory tract in inhabitants of industrial areas.

CONCLUSION

This study eliminates the impact of interfering factors such as age, sex, or the rate of professional vocal effort on the relationship between air pollution and upper respiratory tract disease. Therefore, it can be stated that air pollution (smog) significantly increases the frequency and severity of exacerbations of chronic laryngitis.

meters. It is a mineral chloride-sodium water. It has a certifi- cate confirming medicinal properties issued by the National Institute of Public Health - State Department of Hygiene in Poznan. Hypertonic saline aerosol irritates the mucous mem- brane causing active congestion, increasing secretion of mucous and serum glands, facilitating excretion of sticky, secre- tions from the wall of the respiratory tract [46].

The first scientific data confirming the beneficial effects of the microclimate in the salt chambers for health date back to 1950s.

The main advantages subterraneotherapy include: non-invasive- ness, direct access to the target organ (respiratory tract, skin), fast start of action and less risk of undesirable systemic effects [47, 53]. In addition, the effectiveness of simultaneous admin- istration of other methods is higher and general improvement in psychophysical status of patients is observed [47]. According to scientific data [53].the immediate effect of subterraneotherapy is observed in approximately 15%, whereas after the end of the stay, the positive result was observed in approximately 90%

of patients. A long term effect of therapy (at least 3 months) was observedin around 60% of patients. Like every treatment method, also subterraneoterapy has its limitations. Usually the positive effect of treatment is inversely proportional to the age of patients [54, 55]. Furthermore, usually a one-time stay in salt chamber provides only little benefit. Therapeutic sessions should therefore be repeated, which unfortunately involves more costs for patients [47]. In addition, this type of treatment is not recommended in all patients. In case of hyperthyroidism, pulmonary tuberculosis, epilepsy, dizziness, uncontrolled hypertension, recent myocardial infarction, unstable angina or lung cancer, a consultation with a specialist is necessary [47].

Interestingly, not all patients are aware that subterraneotherapy is available as a method of treatment. The study conducted in 2014 among the inhabitants of Cracow, Rzeszow and Ka- towice [47] revealed that 94% of respondents know about the existence salt caves in their cities. 97% of these people indicate disorders of the respiratory tract as the main reason for ha- lo-therapy. 60% of people are convinced of the favorable influence of halotherapy on human health, and almost 50% be- lieve that microclimate sessions improve well-being, but the positive therapeutic effect is not unequivocal. In this context, it seems important to give the patient full, reliable information regarding possible treatment methods, including subterraneotherapy. Perhaps, in some cases patients will choose natural means for respiratory system rehabilitation instead of relying solely on pharmacotherapy.

Chronic non-specific laryngitis, which is the subject of our study, may be caused by chronic infections, as well factors such as:

tobacco smoke, air pollution and climatic factors, or excessive

Tab. I. Characteristics of the analyzed population

PATIENTS FROM

KRAKOW PATIENTS OUTSIDE OF

CRACOW (> 60 KM)

Sex 15 women

15 men 15 women

15 men

Age 25-35 years: 10

36-45 years: 10

>45 years: 10

25-35 years: 10 36-45 years: 10

>45y ears: 10 Professional use of

voice (+) 10

(-) 20 (+) 10

(-) 20

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ETHICS

The content presented in this article complies with the principles of the Helsinki Declaration, the EU Directives and the unified requirements for biomedical journals. Our own studies were conducted in accordance with the principles of Good Clinical Practice and accepted by the local Bioethics Committee and their participants expressed their agree- ment in writing.

In the context of the quoted references treatment in the resort in Salt Mine “Wieliczka”, included in the protocol of this study, is a form of competent help for a patient suffering from exacerbations of chronic laryngitis. Especially those, who are particularly exposed to the disease exacerbation, including people living in large industrial centers. In addition, it is important to implement the necessary procedures in terms of environmental protection in order to reduce the air pollution, as well as education of the so- ciety on the natural means for treatment of respiratory diseases.

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Access the article online: DOI: 10.5604/01.3001.0010.0128 Table of content: http://otolaryngologypl.com/resources/html/articlesList?issueId=9994 Corresponding author: Remigiusz Ziarno; Studenckie Koło Naukowe przy Klinice Otolaryngologii Uniwersytetu Jagiellońskiego,

e-mail: remik365@gmail.com

Competing interests: The authors declare that they have no competing interests.

Cite this article as: Ziarno R., Suska A., Kulinowski W., Grudzień-Ziarno A., Kostrzon M., Paciorek M., Składzień J.: Does smog affect the incidence of exacerbations of chronic laryngitis? Analysis based on the inhabitants of Lesser Poland Voivodeship.; Otolaryngol Pol 2017; 71 (3): 10-19

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