Lung Function Tests in Hairdressers of Gangtok: A Cross-Sectional Study.

Background: Hairdressers undergo extensive and prolonged exposure to a variety of chemical substances present in the air in their salons. Although in low concentrations, the various products used for hair care are harmful as most of these products generate chemical aerosols during different procedures. These aerosols which have irritant or sensitizing effects on respiratory mucosa have been found to enter into the airways. Aim: The aim of this study is to assess the impairment of lung function in hairdressers in Gangtok. Method: This is a cross-sectional, comparative study conducted on 50 hairdressers and 50 age- and sex-matched non-hairdresser comparison group. The sampling technique used was simple random sampling. Permission from Institutional Ethical Committee was obtained before beginning the study. A standard questionnaire was used to record the respiratory symptoms. The pulmonary function parameters of the subjects were measured using portable spirometer HELIOS 720.
Results: All the parameters were decreased in hairdressers and almost all the differences were statistically significant. FEV1 (P = 0.023) and FEV1/FVC ratio (P < 0.05) were reduced significantly. FEF25-75% and PEFR were also significantly reduced (P < 0.05 in both parameters). FVC was also reduced in hairdressers, but it was not statistically significant (P = 0.342).
Conclusion: Hairdressers undergo exposure to different chemicals in their workplace and carry the risk of decreased pulmonary function. Copyright:

INTRODUCTION

Occupational lung diseases caused by mining and metallurgical activities date back to ancient times in India, and were related to rock cutting and stone carving that were required for building temples and monuments. An increase in these cases began with rapid industrialization. Many such related diseases have been studied which resulted in an awareness of occupational exposure–related diseases, implementation of preventive measures, and an effective decline in the number of cases over the years. However, over the years, there has also been a shift in the substances of occupational exposure related to lung diseases, from coal and silica dust to flour dust and activating substances in confectioneries and agro industries, and irritant substances in cleaning products.[1] In recent years, the highest number of occupational respiratory diseases that has been reported is occupational asthma, with a burden of about 15–20% of the total disease burden of asthma in adults. These are mostly related to allergy to respiratory sensitizing agents like wheat flour (high-molecular-weight) and di-isocyanates (low-molecular-weight) used in baking industries and spray paints respectively.[23] Moreover, there is a continuous development of newer products being launched in the market which has irritant or sensitizing effects on the respiratory mucosa which may either cause asthma or lead to its exacerbation.[4] The beauty industry is one of the fastest rising consumer product industries in India. There is an upsurge in the professional hair care market and the number of hair care professionals is ever growing. The concern is that recent studies have reported that the number of cases of rhinitis and occupational asthma among hairdressers is rising,[5] but too little data is available in this regard in India. Hairdressers undergo extensive and prolonged exposure to a variety of chemicals present in different hair care products like hair colors, hair setting lotions and sprays, hair straightening agents, etc., Such exposures to chemicals which are present in the air in low concentrations are harmful.[67] Most of these products generate chemical aerosols during different hair care procedures which have been found to enter into the lungs. Airways have been found to be sensitive to these chemicals that may enter either through absorption or through inhalation. These chemicals are also known to cause airway irritation that can bring about symptoms related to respiration and reduce pulmonary function. Hence, an increase in the prevalence of rhinitis, bronchitis and different respiratory symptoms have been found among hairdressers.[8] As per previous studies, 5-25% of hairdressing professionals suffer from respiratory diseases.[9] This study is therefore an attempt to find an association between occupational exposure of hairdressers and pulmonary function.

AIMS AND OBJECTIVES

To assess the impairment of lung function among hairdressers in Gangtok.

MATERIALS AND METHODS

This is a cross-sectional and comparative study done as a field survey among various hairdressers in Gangtok after obtaining due clearance from the Institutional Ethical Committee. A written informed consent was taken from all the participants prior to the study. The sample size of the study was 50 and the comparison group also consisted of the same number of participants. The sampling technique used was random sampling. All the beauty salons in Gangtok were enumerated which were 63 in number. Out of these, 25 salons were chosen using the lottery system. A total of 112 hairdressers were enumerated and of these 68 fitted the inclusion criteria. Out of these 68, 50 hairdressers were chosen using the lottery system. The same number of participants for the comparison group were chosen from different private offices in the same locality again by simple random sampling using the lottery system. The comparative group was age- and sex-matched to eliminate the confounding factors, and hence the error in observation and comparison. Inclusion criteria for the study group was that the hair care professionals were to have a minimum of one year of full-time hairdressing experience. The participants were made to fill a pro forma which included socio-economic data. A standard questionnaire regarding respiratory symptoms along with any significant medical history was filled and a record of smoking and tobacco consumption was also made. After completing the questionnaire, each study participant was subjected to body weight measurement (to the nearest 0.1 kg) using a portable electronic scale. Standing height was measured to the nearest 1 mm without shoes in Frankford position using a portable stadiometer. Body mass index (BMI) was calculated as weight in kilograms (kg) divided by height in meter squared (m2). Persons with a history of respiratory disease, cardiovascular disease, smoking or taking medication for allergy or respiratory disease were excluded from the study sample.

Pulmonary function tests (PFTs) were conducted on the hairdresser and comparison groups in their respective workplaces with the help of a portable spirometer HELIOS 720. The PFT was done in standing position as per American Thoracic Society guidelines and all precautions to eliminate errors were taken. The participants were demonstrated on how to perform the test (with the nose occluded and forced inspiration, forced expiration and inspiration again in that order into the mouthpiece). The parameters recorded were forced vital capacity (FVC), forced expiratory volume in first second (FEV1), peak expiratory flow rate (PEFR), forced expiratory flow (FEF25%, 50% and 75%) and FEF25–75%.

Data analysis

Descriptive statistics was used to summarize the demographic variables. The PFT values were expressed as mean ± Standard Deviation. SPSS software version 20 was used to carry out analytical studies. A P < 0.05 was taken as significant. Comparison was done between the predicted values of PFT parameters in hairdressers and apparently healthy group using independent t test. Same test was done to compare the FVC, FEV1, FVC/FEV1, FEF25–75% and PEFR of the study group with that of the comparison group. Paired t test was used to compare predicted and actual spirometry values. Predicted and actual spirometry values were used to calculate percentage function. Reduction in function of less than 80% of predicted value was considered as drop in function of respective spirometry values. PFT values less than 80% of the predicted values was used to estimate drop in function categorically. A Chi-squared test was used to associate drop in function with occupational status. Similarly, a Chi-squared test was done to test the significance of association between respiratory symptoms and hairdressing occupation.

RESULT

The average age of hairdressers was 27.3 ± 6.36 years and that of apparently healthy comparison group was 25.70 ± 4.78 years. There was no difference in age and anthropometry (BMI) of hairdressers and comparison group (P = 0.92) as shown in Table 1.

Table 1

Anthropometric Parameters

Parameters	Hairdressers Mean±SD (n=50)	Apparently healthy comparison group Mean±SD (n=50)	P
Age (years)	27.3±6.36	26.7±4.78	0.8
Height (m)	1.56±0.07	1.59±0.06	0.15
Weight (kg)	60.24±9.04	61.8±9.05	0.75
Body mass index (BMI) (kg/m2)	23.61±3.63	24.31±3.09	0.92

Almost half of the hairdressers are in this profession for more than five years and the rest had an exposure of the same for a period of 1–4 years. Respiratory symptoms like cough and production of phlegm was found in 14% of hairdressers as compared to only 4% in the comparison group but this difference was not statistically significant (χ2 = 3.052, df = 1, P > 0.05). Similarly, complaint of another respiratory symptom, breathlessness, after mild exercise (walking, climbing stairs) was found in 10% of the hairdressers as opposed to 5% reported by the age-matched comparison group; but even this difference was not statistically significant (χ2 = 0.3, df = 1, P > 0.05).

For the purpose of standardization, a comparison of predicted values of lung function tests in the hairdresser and comparison groups was done as shown in Table 2. P < 0.05 was taken as significant.

Table 2

Comparison of predicted values of PFT in hairdressers and apparently healthy comparison group

PFT	Hairdressers Mean±SD (n=50)	Apparently healthy comparison group Mean±SD (n=50)	P
FVC in liters (L)	2.53±0.58	2.75±0.575	0.061
FEV1 (L)	2.07±0.48	2.26±0.529	0.063
FEV1/FVC	82.39±2.99	83.56±3.1	0.067
FEF25-75% (L/Sec)	3.10±0.70	3.33±0.63	0.087
PEFR (L/sec)	6.65±1.24	6.98±1.32	0.216

Statistically, there was no significant difference in the predicted PFT values between the two groups. Therefore, an independent t test was done to compare the absolute FVC, FEV1, FVC/FEV1, FEF25–75% and PEFR values of the hairdresser group with that of the comparison group. P < 0.05 was taken as significant. The lung function profile for both the hairdresser cohort and normal cohort is shown in Table 3.

Table 3

Comparison of lung function tests in the hairdresser and apparently healthy comparison groups

PFT parameters	Hairdressers Mean±SD (n=50)	Apparently healthy comparison group Mean±SD (n=50)	P
FVC in liters (L)	2.36±0.57	2.47±0.59	0.342
FEV1 (L)	2.16±0.54	2.42±0.56	0.023*
FEV1/FVC	91.95±8.49	98.13±3.05	0.000**
FEF25-75% (L/Sec)	2.87±0.97	4.04±0.89	0.000**
PEFR (L/sec)	4.28±1.48	6.31±1.58	0.000**

*P <0.05 is considered significant

The FVC values were lower in the study group than in the comparison group though the difference between the two groups was statistically insignificant. The mean FEV1 values were found to be significantly reduced in the study group than in the comparison group. The FEV1/FVC ratio of the study group was also significantly reduced than that of the comparison group. Similarly, the values for FEF25–75% as well as PEFR in the hairdresser group was significantly reduced than that in the comparison group.

The drop in function was significantly associated with hairdressers with respect to PEFR as compared to apparently healthy individuals. (χ2 = 29.873, df = 1, P < 0.05) as given in Table 4 and Figure 1. There was significant decrease of PEFR in 84% of the participants in hairdresser group as compared to 24% of the participants in the comparison group.

Table 4

Association between drop in lung function and hairdresser group

PFT variables	χ2, (df), P
FVC in liters (L)	0.125, (1), 0.724
FEV1 (L)	0.175, (1), 0.675
PEFR (L/sec)	29.873, (1), 0.00*

*P <0.05 is considered significant

Figure 1

Number of participants who demonstrated decreased lung function in both hairdresser and non-hairdresser comparison groups

DISCUSSION

To the best of our knowledge, this is the first study to explore pulmonary function tests regarding occupational exposure in hairdressers in Gangtok. Spirometry was performed and the parameters under examination were FVC, FEV1, FEV1/FVC, PEFR, FEF25–75%. There was no significant difference between the predictive values of PFT in both the groups probably because the comparison group was age- and sex-matched. In this study, all the parameters of PFT under the study except FVC were found to be decreased in the hairdresser group and this decrease was found to be statistically significant. The value of FVC in the hairdressers was also lower than the non- hairdressers but it was not statistically significant. FEV1, which is a marker of airway obstruction, was significantly reduced in the study group. Krstev S, et al.[10] in their study found that the correlation between asthma and hairdressers’ occupational exposure was very significant. This is similar to the results of our study. Quaternary ammonium compounds, which is a part of the ingredients of different products used by hairdressers, have a sensitizing effect on the airway mucosa and may be one of the causes of obstructive features in exposed workers. The process of making solutions for bleaching, which is one of the procedures of changing hair color, generates aerosols which may enter the respiratory tract lining through inhalation and cause respiratory symptoms.[11] The findings of another study done by Heibati et al. was that the lung functions were compromised in most of the exposed hairdressers as compared to the unexposed group. They found that the most common deficit was the restrictive type followed by the obstructive type which does not match with the findings of our study. The exposed group had more complaints of symptoms related to the respiratory system than the unexposed group though the potential confounders were adjusted.[12] In a five-year follow-up study, it was seen that the duration of work is directly proportional to the decline in respiratory function. It was also seen that a few hairdressers even left their jobs because of developing respiratory symptoms.[13] A study done in Iran also found that a significantly lower value of FVC as well as FEV1 was seen in the hairdressers than in the unexposed group.[14] Ammonium persulfate has been noted to be markedly harmful to the respiratory tract and is responsible for nearly 90% of respiratory diseases. Almost 37.5% of the hairdressers had to change their job during a three-year follow up.[15] Another study by Quiros-Alcala et al.[11] concluded that there is definite indication that the hairdressing profession may increase the chances of developing respiratory diseases. There are many potentially harmful chemicals that a hairdresser gets exposed to and the most common are hair conditioners, bleaching agents, hair coloring products, fixers, and hair relaxing and straightening agents.[7] Chemicals that hairdressers are mostly exposed to include formaldehyde, ammonia, sodium and potassium salts of peroxydisulfuric acid, ethanol, P-phenylene diamine, glycerol thio-glycolate, etc., found in shampoos, hair colors, hair fixers, hair bleaches, and in reagents used to curl hair permanently.[711]

As most of the studies show a decline in lung function in the hairdressers, this population of workers need to be taken care of. Moreover, a majority of them in our study were not aware of the possible harmful effects of the chemicals that they were exposed to. More studies, especially longitudinal studies with a pre-employment lung function data and measurement of actual air concentrations of chemicals from the salons will give clearer results. Future research in this regard is warranted for.

The limitations of our study are small sample size and lack of pre-employment lung function status. The measurement of concentration of chemicals in the salon environment was also not done.

CONCLUSION

Occupational exposure of hairdressers carries the risk of impairment of lung function and development of respiratory symptoms. PFT values were significantly decreased, especially FEV1 and PEFR in hairdressers than among the general population. This may indicate development of obstructive lung disease in the exposed workers. Respiratory symptoms like cough and phlegm production were also found to be higher among hairdressers than among the general population, though the difference was not statistically significant. As this is preventable, initiatives should be taken to improve the working conditions of hairdressers and, increase awareness among them and the employers regarding the usefulness of protective equipment and protective behaviors during working hours to minimize exposure. Pulmonary function tests prior to employment and periodic testing of the employed hairdressers will help with early identification of decreased lung function and worsening of pre-existing respiratory diseases, if any.

Financial support and sponsorship

TMA Pai and Vasanthi Pai Endowment fund, Sikkim Manipal University.

Conflicts of interest

There are no conflicts of interest.