Acute respiratory symptoms and its associated factors among mothers who have under five-years-old children in northwest, Ethiopia

Poor air quality of the household is likely to be the largest human health concern in modern society [1]. In households with poor ventilation (as it is common in many low- and middle-income countries), exposures experienced by household members, particularly women and young children who spend a large proportion of their time indoors, have been documented to be many times higher to develop respiratory symptoms [2]. An increasing number of evidences have associated housing quality with morbidity and mortality from infectious diseases, chronic illnesses, injuries, poor nutrition, and mental disorders [3, 4]. Each year, close to 4 million people die prematurely from illness attributable to household air pollution from inefficient cooking practices using polluting stoves along with solid fuels such as dung, wood, agricultural residues, coal, and kerosene. Among these 4 million deaths, 27% are due to pneumonia, 18% from stroke, 27% from ischemic heart disease, 20% from chronic obstructive pulmonary disease (COPD), and 8% from lung cancer [5]. The magnitude of respiratory symptoms varies across countries. Evidence from a recent epidemiologic study conducted among adult residents in Guizhou province, China showed the prevalence of asthma-like symptoms, and asthma was 13.1% in winter [6]. The prevalence of respiratory symptoms among workers reported in Iran and Thailand varies from 15.5% [7] to 41% [8]. The self-reported respiratory symptom prevalence among women using traditional stoves in rural Honduras was 82% [9]. The prevalence of self-reported respiratory symptoms among Ethiopian women was 41.8% [10]. A study was done in Debre Berhan, Ethiopia demonstrated that the prevalence of bronchial asthma among adult patients was 29.6% [11]. Another comparative study carried out among textile factory workers in the northwest, Ethiopia revealed that the prevalence of self-reported respiratory symptoms in the slum areas of Addis Ababa and four rural kebeles of Butajira was 47.8% [12].

Poor housing conditions are associated with a wide range of health problems, including respiratory infections, asthma, lead poisoning, injuries, and mental health. It has a multitude of adverse health consequences on a woman as well. For instance, exposure to air pollutants during pregnancy can potentially impede fetal development and cause several ill birth outcomes such as intrauterine growth retardation, prematurity, abortion, low birth weight, congenital anomalies, and, in cases that are more severe, intrauterine or perinatal death [3, 13].

Among the diverse environmental concerns facing low- and middle-income countries including Ethiopia, housing is the most fundamental one. Most urban settings in low- and middle-income countries were not designed to handle millions of people which directly impact the availability and affordability of housing, forcing millions to live in substandard dwellings with poor housing quality [14]. Poor household air quality and housing, as well as crowding, are still typical basic problems of growing settlements and megacities, most of which are located in low- and middle-income countries [15].

However, in low- and middle-income countries, there are many relevant housing and health challenges still to be averted. Earlier studies have identified that different factors have been correlated with respiratory symptoms among mothers who have under five-year-old children. For instance: second-hand tobacco smoke, involvement in the charcoal production business, weaving, annual mean concentrations of NO₂, total suspended particulates, particulates of less than 10 μm in aerodynamic diameter (PM10), ventilation, spinning, involvement in burning grass/field were significantly associated with respiratory symptoms [12, 16‐18].

Evidences generated from this study would enable policymakers and program managers, administrators, Zonal health bureau, and other related stakeholders who work on this issue to understand the burden of the problem and its possible negative consequences which in turn direct them to a way of taking prompt actions and measures to alleviate the problem. The main objective of this study is to assess acute respiratory symptoms and its associated factors among mothers who have under five-year-old children in Gondar city, northwest Ethiopia.

The overall prevalence of respiratory symptoms in the current study was 46.1% at 95% [CI: 42.6%–49.7%]. This result is lower than self-reported respiratory symptoms from rural Honduras [9] and South India [21]. However, the prevalence was higher than respiratory involvement among women exposed to the smoke of traditional biomass and gas fuel in Bangladesh [22], respiratory symptoms in Indian women [23], and women in West Sierra Leone [24]. The prevalence is closer to an earlier report from Ethiopia [10]. The differences in the proportion of self-reported respiratory symptoms may be attributed to a difference in the level of socioeconomic status, housing conditions, fuel type used, measurement difference, and study period.

Educational status was associated with mothers' respiratory symptoms. Mothers who attended technical and vocational training were less likely to develop respiratory symptoms as compared to those who cannot read and write. Lower educational status was reported as a risk factor for asthma and respiratory symptoms in many cross-sectional studies [25‐28] and a cohort study [29]. The reason for the association of educational status and respiratory symptoms might be due to the fact that educational status is among the most common indicators used for measurement of socioeconomic status [30]. Educational level was associated with income and the capacity to buy clean fuel in a previous study [31] and lower educational level was more strongly associated with biofuel use which results in a higher risk of respiratory infection [32, 33].

In our analysis, the adjusted odds ratio of respiratory symptom was 2.9-folds among mothers working in dusty and smelly environment compared to those who reported working in a clean environment. The effects of occupational dust exposure on the reduction of pulmonary function and aggravation of respiratory symptoms have long been confirmed [34‐36]. Exposure to dust results in a reduction of lung function due to pulmonary obstruction, and dust particles serve as a vehicle for disease-causing microorganisms [35, 36]. The chemical composition of dust may also be responsible for respiratory symptoms [37, 38].

Fuel type usually used for cooking is another factor associated with respiratory symptoms in this study. The use of open firewood was protective against respiratory symptoms as compared to charcoal use in the current study. This is against reports from several earlier evidence [39, 40], whereby charcoal was better than an open fire and firewood in terms of a respiratory outcome as coal produces less particulate matter than open fire and wood. Even though charcoal is often considered as a clean fuel compared to the other biomass fuels, such as firewood, animal dung, crop residues [41, 42], Das et al. [39] and Sana et al. [43], consistent to the present study, found positive associations between respiratory symptoms and firewood compared to charcoal. Sana et al. [43] reported that charcoal is not easy to set on fire, and the cooks usually use fire starters such as plastic bags, tire rubber cut or inner tire tubes, drainage oil, paper, agricultural waste, petrol coke powder, twigs, and dry herbs. Plastic especially releases toxic gases like dioxins, furans, mercury, and polychlorinated biphenyls, as well as some additives as phthalates and brominated flame retardants which pose respiratory health risks [44].

Mothers who reside at houses painted in the past 6 months prior to the study were at higher odds of respiratory symptoms. Indoor paints may emit harmful chemicals that result in respiratory irritation [45]. Recent indoor painting was reported as one of the risk factors to respiratory symptoms in several previous studies [45‐50].

Study participants who live in houses and reported pesticide use were at higher risk of respiratory symptoms. This was in line with an earlier study [51]. The potential plausibility of the observed association can be explained by the toxicological and clinical nature of the pesticides. Most pesticides have low molecular weight, which enables them to induce immediate humoral immune-mediated allergic reactions [52, 53]. Exposure to organo chlorines at high concentrations may result in mucus hypersecretion and airway smooth muscle contraction leading to breathlessness, wheezing, and cough [54]. It favors the T-helper cell (Th) type 2 immunophenotype associated with asthma and allergy [55].

Living within 100 m of the unpaved road was a risk factor for respiratory symptoms in the sense of exposure to outdoor air pollutants. There is well-established evidence that exposure to air pollution results in a higher risk of a respiratory infection such as pneumonia [56‐61].

The presence of damp stain was another risk factor affecting respiratory symptoms, and this is not surprising as mold growth is favored in damp conditions [62, 63]. In the current study, the presence of new carpet in the house was a risk factor for respiratory symptoms among women. The presence of new furniture such as carpet has been associated with respiratory illnesses in several earlier studies [64, 65]. Carpets harbor house dust and thereby respiratory illness-causing pathogens [66].

Respondents who spend much of their time (6 to 11) hours and (11 to 15) hours indoors had 2.59 and 3.47 high odds of facing respiratory symptoms compared with those who spent a few hours (< 6 h), respectively. Even though the current study has shown spending a long time in indoor environments is a risk for acute respiratory symptoms, this is not consistent with spending more than 15 h indoors. Perhaps, those who spend their time indoors may have kept the house and ventilation and their surrounding environments clean.

Lastly, study participants who live in houses made up of wood and mud were at higher risk of respiratory symptoms.

Although large sample size and simple random sampling employed in this study which helps for greater generalizability, lack of measurements, i.e., pulmonary function test and inherent nature of the cross-sectional study which fails to show cause–effect relationships were the limitations of this study. In addition, recall and social desirability biases might be high in such types of self-reported cross-sectional studies.

The overall prevalence of respiratory symptoms was relatively high among mothers who have under five-years-old children. Several modifiable factors such as educational level, working in a dusty environment, fuel type used for cooking, recent house painting, presence of new carpet and damp stain, pesticide use, living in mud- and wood-walled houses, spending longer time indoors, and living near unpaved roads/streets were found to be significantly associated with respiratory symptoms among mothers. Thus, we recommend policymakers and implementers to engage in household air quality improvements, fuel selection, and residential house planning to help mothers protect from respiratory symptoms.