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 Table of Contents  
Year : 2015  |  Volume : 3  |  Issue : 4  |  Page : 212-217

Infertility and its relationship with NO 2 pollution in Iran from 2009 to 2012

1 PhD Student of Health Crisis Management, Department of Management, Research Institute of Shakhes Pajouh, Isfahan, Iran
2 Research Institute of Shakhes Pajouh Chancellor, Department of Civil Engineering, Isfahan, Iran
3 Professor at Research Institute of Shakhes Pajouh Isfahan, Isfahan, Iran

Date of Web Publication11-Aug-2015

Correspondence Address:
Zeinab Rashidi
Health Crisis Management, Research Institute of Shakhes Pajouh, University of Isfahan, Isfahan
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/2347-9019.162558

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Background: National Institute of Environmental Health Sciences scientists show that long-term exposure to air pollutants increases the risk of infertility. NO 2 factor is considered as one of the underlying causes of infertility diseases. This study aimed to determine the association of infertility diseases documented in medical records and NO 2 accumulation in Iran. By plotting the prevalence and spatial distribution maps, important differences from different points can be observed. Materials and Methods: In this study, the first challenge was to collect some relevant information. In this connection, the authors managed to gain access to data concerning infertility in Iran. The data, which had been collected by Country Health Centre, provided information from 2009 to 2012. To measure spatial distribution of NO 2 pollutions we used ozone monitoring instrument. Using geographic information system (GIS), the researchers drew the map of the spatial distribution of infertility in the country and then we used Neural Network model (NN) to obtain relation between air-pollution and infertility data, that NO 2 data obtained using zonal statistics in GIS. Results: Space with tracing the distribution of infertility diseases was scattered based on the distribution of NO 2 pollution in the points is an important part of this type of diseases in Iran where air-pollution was more abundant. Finding: The findings of this study emphasis on the importance of preventing the exposure to air-pollution, and to control air-pollution producing industries, to improve work environmental health, and to increase the health professionals and public knowledge in this regard. Conclusion: The analysis revealed to what extent NO 2 explained the observed infertility incidence values. NN analyses were performed (at the 99% confidence level in training data and 88% in validation).

Keywords: Infertility diseases, Iran, NO 2 pollution, spatial distribution

How to cite this article:
Rashidi Z, Mahmuodzade A, Ghazi I. Infertility and its relationship with NO 2 pollution in Iran from 2009 to 2012. Int J Health Syst Disaster Manage 2015;3:212-7

How to cite this URL:
Rashidi Z, Mahmuodzade A, Ghazi I. Infertility and its relationship with NO 2 pollution in Iran from 2009 to 2012. Int J Health Syst Disaster Manage [serial online] 2015 [cited 2019 Aug 24];3:212-7. Available from: http://www.ijhsdm.org/text.asp?2015/3/4/212/162558

  Introduction Top

At the end of autumn, each year, we used to witness unhealthy air due to temperature inversion, especially in large cities. In year 2010, Iran broke its last year's inversion record of 42 days by a surpassing 45-day inversion period. Scientist believes the reason for this phenomenon lies in greenhouse effect due to the accumulation of air pollutant such as CO, CO 2 , NO 2 , SO 2 , O 3 , and floating particulate matters or aerosols. Increase in the number of days with air-pollution and red alerts in big cities affects all aspects of health, especially those of the children, the elderly, and pregnant women. [1] Numerous studies have been done on the impact of air-pollution on the cardiovascular and pulmonary functions. [2] A number of studies have evaluated the relationship between the impact of air-pollution on human and other mammalian reproductive function. Air-pollution increases the rate of abortions, low birth weight or increase in the number of anomalies, and congenital defects due to maternal exposure to polluted air during pregnancy. [3] Cigarette smoking is a good example in both men and women as it can harm oogenesis, spermatogenesis, sperm, and ovum quality leading to intrauterine growth retardation and increased risk of abortion. [4] Infertility is an increasingly common reproductive dysfunction that affects over 10% of couples worldwide, which translates into roughly 80 million couples. [5] Increased industrialization as well as the rise in the incidence of infertility has stimulated the scientific community to begin exploring possible nexus between infertility and environmental factors. Such a view may be justified on the ground that contemporary life involves unavoidable interface with the biologically active products of industrial and agricultural processes that continuously alter the physical, chemical, and thermal environment. Infertility has been recognized as a potentially serious, costly, and burdensome problem on affected families. Infertility may have far-reaching consequences, including marital conflicts, violence, stigmatization, isolation, and divorce. [6] The consequences are more serious in societies where women are primarily stereotyped as mothers. The exposure of the couples to pollutions may cause chromosomal abnormalities and infertility of their. [7] For example there are an association between reduced fertility rates and air-pollution levels. [8] Overall, the environmental pollution is one of the factors contributing to the decrease of sperm quality for human beings. [9] Male reproductive health may be threatened by environmental pollution. In recent years, declining sperm counts and quality become an important health issue because of environmental pollution. [10],[11] Today, mankind unavoidably comes in contact with several non-self-environmental factors such as heavy metals and several chemicals many of which can modulate biological systems to influence physiology and promote disease states. [12] Al-Saleh et al. argued that exposure to environmental factors exert varying effects on fertility. As noted earlier, mankind faces a number of unavoidable nonself-environmental factors which include: Heavy metals, chemicals, heat, and sociocultural factors. [13] Several heavy metals are present in the environment in amounts alarmingly unsafe for human health, as exposure occurs via food and water. [14] It is alarming to note that in Asia, rice and products such as rice bran and rice crackers have elevated levels of As. The current study was an attempt to the epidemiology of infertility and its relationship with NO 2 in Iran from 2009 to 2012.

  Materials and Methods Top

In this study, the first challenge was to collect some relevant information. In this connection, the authors managed to gain access to data concerning infertility in Iran. The data, which had been collected by Country Health Centre, provided information from 2009 to 2012. To measure spatial distribution of NO 2 pollutions we used ozone monitoring instrument (OMI). OMI measures criteria pollutants such as O 3 , NO 2 , SO 2 , and aerosols. The US Environmental Protection Agency (EPA) has designated these atmospheric constituents as posing serious threats to human health and agricultural productivity. These measurements are made at near urban scale resolution and track industrial pollution and biomass burning. Using geographic information system (GIS), the researchers drew the map of the spatial distribution of infertility in the country and then we used Neural Network model (NN) to obtain relation between air-pollution and infertility data, that NO 2 data obtained using zonal statistics in GIS.

What is a neural network?

An Artificial Neural Network (ANN) is an information processing paradigm that is inspired by the way biological nervous systems such as the brain, process information. The key element of this paradigm is the novel structure of the information processing system. It is composed of a large number of highly interconnected processing elements (neurons) working in unison to solve specific problems. ANNs, like people, learn by example. An ANN is configured for a specific application, such as pattern recognition or data classification, through a learning process. Learning in biological systems involves adjustments to the synaptic connections that exist between the neurons (this is true for ANNs as well).

  Results Top

In a total number of 21,051 infertile couples, the age range was between 22 and 45 years. The infertility period was <5 years. In Iran, annual NO 2 concentrations increasing throughout 2009-2012 [Figure 1],[Figure 2],[Figure 3] and [Figure 4] followed by increasing concentrations in the 2012's epidemiology of infertile couples in Iran in polluted areas was highest than the other areas. The potential relationship of NO 2 in Iran on infertility incidence was examined using a NN. To test the hypothesis, "Do NO 2 samples collected in country have an impact on infertility incidence values?" The analysis revealed to what extent NO 2 explained the observed infertility incidence values. NN analyses were performed (at the 99% confidence level in training data and 88% in validation) [Figure 5]. Nitrogen dioxide belongs to a family of highly reactive gases called nitrogen oxides (NOx). These gases form when fuel is burned at high temperatures, and come principally from motor vehicle exhaust and stationary sources such as electric utilities and industrial boilers. A suffocating, brownish gas, nitrogen dioxide is a strong oxidizing agent that reacts in the air to form corrosive nitric acid, as well as toxic organic nitrates. It also plays a major role in the atmospheric reactions that produce ground-level ozone (or smog). Health and Environmental Effects: Nitrogen dioxide can irritate the lungs and lowers resistance to respiratory infections like influenza. The effects of short-term exposure are still unclear, but continued or frequent exposure to concentrations that are typically much higher than those normally found in the ambient air may cause increased incidence of acute respiratory illness in children. EPA's health-based national air quality standard for NO 2 is 0.053 ppm (measured as an annual arithmetic mean concentration). The detrimental effects of air pollutants such as NO 2 has been implicated in poor semen quality. [15] According to different geographical conditions, human health in different sub-regions of the world and environmental pollutions, the main factor of infertility has a heterogeneous list of causes in the world. Therefore, we decided to investigate the epidemiology of infertility in Iran [Table 1] and [Table 2].
Figure 1: Air-pollution distribution in 2012 (NO2) (1015 molec/cm2)

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Figure 2: Air-pollution distribution in 2011 (NO2) (1015 molec/cm2)

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Figure 3: Air-pollution distribution in 2010 (NO2) (1015 molec/cm2)

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Figure 4: Air-pollution distribution in 2009 (NO2) (1015 molec/cm2)

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Figure 5: Neural network analysis of infertility and NO2

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Table 1: Effects of air-pollution on human health[16]

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Table 2: Remote sensing instrument comparison chart (NASA)[17,18]

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  Discussion Top

The population includes 21051 records from infertile couples in the country. NO 2 pollution in provinces such as Tehran, Khuzestan, Mazandaran, and Golestan, according to survey, is more than the other provinces because vehicles' traveling is higher in these provinces shows the provinces with high pollution in Iran and it seems fertility rate is higher in these areas.

The time range of this study, according to the number of samples, is sufficiently reliable and over 5 years (4 years from 2009 to early 2012 was considered). Impaired synthesis of hemoglobin and anemia, respiratory diseases, malignant disease, hypertension, kidney damage, miscarriages and premature infants, nervous system disorders, brain damage, infertility, loss of learning, and behavioral disorders in children form the negative effects of high concentrations of the air-pollution in the body. Air-pollution exists naturally in the environment, but in most cases, the increase in quantity is the result of vehicles traveling. The role of air-pollution in emergence of infertility diseases in urban communities is considered as an effective factor that could not be modified, such that comforting environmental pollution has been considered relative to different infertility effects including female infertility or male infertility failures. Infertility disease is the bitter achievement of advances in technology. The useful role of technology somewhat allows people to have longer life and the harmful role of technology provides the change in life style and immobility. In a report by Veras et al.,[19] the results shown reinforce the idea that maternal exposure to air-pollution is linked to negative pregnancy outcomes, even if the exposure occurs only before conception. Pollution factors play a major role in infertility in Africa. One of the most important health problems in Sub-Saharan Africa is the high rate of infertility and childlessness. [20] Conflicting results from different studies could be due to different cultural, social, economic, and environmental situations in each country that are affected by the epidemiologic characterization of infertility. [21] It seems that various factors can affect the reproductive ability of couples. Many of these causes are not yet known. Obviously, the increasing environmental pollution in industrial cities affects couples fertility. Considering the more contributory role of air-pollution in infertile couples in the existing studies including the current study, the reduction of NO 2 might reduce the risk of infertility. Since the quality of individual and social life is related to fertility state, it seems that more comprehensive studies on factors affecting fertility at the community level are justified and recommended.

  Conclusion Top

By drawing the geographical distribution of fertility diseases [Figure 6] it was observed that the rate of disease is higher in some provinces, which this can be a reason: Vehicles traveling is higher in these provinces such as Mazandaran, Tehran, and Khuzestan, environmental pollutions including the existence of some specific elements and hard urban life, all express the verification of the hypothesis. Since the basis for campaign against nonepidemic diseases, including infertility disease is changing people's life style, it seems that it can be achieved by instructions and training people, making required polices and enacting laws and necessary regulations to provide an environment that is suitable for promoting healthy behaviors in life. By proper intervention in the society, the effects of risk factors could be totally eliminated or reduced. Even partial changes could be very useful. Prevention is possible by intervening the risk factors in infertility diseases such as identification of some elements in the environment and finding the place of their distribution, avoiding the use of air pollutants or using them as little as possible, proper use of technology, changing diets, behaviors, physical habits, reducing anxieties and mental stresses, and other environmental diseases.
Figure 6: Epidemiology of infertile couples (2009-2012) ratio to population per 100,000 people

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Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

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  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6]

  [Table 1], [Table 2]


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