According to the Development Bank of Latin America – CAF, the minimal productivity in Ecuador and other Latin American countries is represented by low or null innovation, inefficient employment, and uneven capital distribution [1], [2]. This is reflected in the decrease of 80% of the investments in health and education, while, investments in transport infrastructure are the highest and remain invariable comparing the years 2021 versus 2022 [3]. Moreover, in Ecuador, several environmental challenges are experienced and expected to worsen in the coming years. Considering its size, Ecuador has the highest annual deforestation rate of any country in the Western Hemisphere and there is a significant loss of forest biomass. The country’s fossil fuel dependence, plus large-scale agricultural projects resulted in a significant depletion of natural resources, biodiversity, and important contributions to environmental pollution [4]. Furthermore, the majority of anthropogenic projects did not receive an efficient environmental assessment since the political and economic power is not focused on the well-being of the society. The reduced number of reported environmental studies evaluate the impacts of water or air pollution on Ecuadorians, mainly living in the capital, but little to no attention has been given to the effects of environmental pollution on citizens from small cities [5]–[9]. Noise pollution is a globally growing problem that is rapidly increasing and affecting the population at all stages of life. Moreover, a large part of the population does not realize how it affects their health. In Ecuador, only a few reported scientific studies evaluate the effect of noise pollution on the population [5], [6], [10]. Accordingly, the most vulnerable to noise health threats are pregnant women, fetuses, newborns, infants, and children commonly gathering at workplaces, commercial and industrial areas, hospitals, and educational institutions [11]. Pregnant women and children exposed to loud sounds for a prolonged time have a higher risk of having temporary or permanent hearing loss depending on the loudness and duration of exposure [11]. Thus, there is a need for frequent and strict controls of noise levels, the implementation of protective measures, and public education regarding the health hazards of noise.
Focusing on noise levels at hospitals and mainly at NICUs, special attention is needed. These areas are designed to support the recovery and evolution of premature newborns or those with harsh diseases that require special care [12]–[14]. These are usually classified into basic, intermediate, and intensive care units, according to the treatments and care that newborns need for their recovery and growth [15]. NICUs must meet some minimum environmental quality criteria, so that newborns have adequate conditions for their growth, during the first months of life [16]. An appropriate level of light, temperature, humidity, oxygen, and absence of noise are important factors that require permanent control.
Several studies have shown that noise in NICUs has a clear relationship with the newborn's physiological, neurological, and motor development. Excessive noise generates adverse effects such as sleep disorders, poor development of responses to stimuli, affectation of the nervous system, growth delays, and even decreased hearing capacity [17]–[19]. Newborns in NICUs are exposed to an overload of sound stimuli from different sources such as the ones generated by the alarms of the medical equipment, telephones, conversations of the medical personnel, the closing, and opening of doors, monitors, incubators, ventilatory circuits, visitors and, cleaning staff shifts, among others [13], [14], [16]–[20]. The majority of reported cases concluded that recorded noise levels exceed the suggested limits by the WHO, the United States Environmental Protection Agency (EPA), and American Academy of Pediatrics (AAP), and/or Ecuadorian environmental regulations such as the Unified Text of Secondary Environmental Legislation (TULSMA) [13], [21]. On average, the noise levels in these units can range from 50 to 75 dBA, sometimes they present peaks that exceed 100 dBA and some prolonged sounds remain in ranges of 70 to 80 dBA [14], [22]–[24].
Until 2018, the WHO reported that 15 million babies are born preterm each year and that the tendency keeps increasing [25]. In 2019, the National Institute of Statistics and Censuses of Ecuador (INEC), informed that 18.8% of all fetal deaths correspond to preterm babies born between weeks 36 and 38 of gestation [26]. The same year, from a total of 285,827 newborns, 5.1% were premature, thus, received specialized care at NICUs. Certainly, NICUs have ensured the well-being and survival of babies; however, neonatal hospitalized in these areas are exposed to constant noise associated with the monitoring and follow-up of their vital signs [27], and to environmental factors that could harm their physical conditions [20]. Newborns tend to show signs of stress or forms of self-regulation as a defense mechanism against possible disturbances, these are intended to control them; however, the energy they need is mainly for their recovery processes [28]. The physiological effects that are manifested in newborns due to noisy stimuli are hypoxemia, bradycardia, increased intracranial pressure, arterial hypertension, apnea, stress, disorganized behaviors, and metabolic instability since their caloric requirements increase from glucose; in addition, sleep disturbances, irritability, tiredness, nausea, and loss of appetite occur [29].
The AAP establishes a series of recommendations to minimize noise levels in NICUs by improving their management and promoting research to determine the effects of noise on pregnant women, their fetuses, and newborns. EPA establishes not to exceed 45 dBA for the daytime period and 35 dBA for the nighttime period inside hospitals, in addition, the AAP ratifies the importance of monitoring noise levels inside NICUs, showing a maximum noise level of 45 dBA [30]. Table 1 shows a compilation of maximum acceptable noise levels established in the TULSMA [21].
Table 1
Compilation of maximum noise levels
Agencies, Organizations, and Regulations | Equivalent Continuous Sound Pressure Level, or Leq/LAeq (dB) |
Day | Night |
7h01–21h00 | 21h01–7h00 |
Environmental Protection Agency (EPA) | 45 | 35 |
American Academy of Pediatrics (AAP) | 45 | 45 |
Clinical Practice Guideline (CPG) | 40 | 40 |
Spanish Association of Pediatrics (AEP) | 45 | 45 |
World Health Organization (WHO) | 30 | 40 |
Ministerial Agreement 097 Annex 5. Maximum noise emission levels and measurement methodology for fixed and mobile sources (TULSMA) | 55 | 45 |
In this sense, the objectives of this study are to identify, characterize, and assess the noise levels in the NICU of a typical medium-sized hospital in the region of Loja, Ecuador. Subsequently, an evaluation of the main correlations of the noise sources is carried out, so that the right protection measures for noise reduction and elimination can be proposed.