Information on journals and articles
In five environmental health journals, 1,679 articles were published in 135 issues over twelve years. Of the 883 articles, 529 (30.3%) were in the field of water pollution, 196 (11.22%) air pollution and 158 (9.1%) solid waste management (Table 1).
International Collaboration In The Compilation Of Articles
Of the 883 articles in the three fields of water and air pollution and solid waste management, 123 articles (13.9%) were written by researchers from other countries, 67 (54.57%) of which were related to water pollution, 29 articles (23.53%) were on air pollution and 27 articles (21.9%) on waste management (Fig. 1).
Number And Gender Of Authors
The 883 articles in the three fields of water and air pollution and solid waste management were written by 3,145 researchers, and 760 of the articles were exclusively written by 2,739 Iranian researchers, the minimum and maximum number of authors ranging from 1 to 18 (3.75 ± 1.5). In the 123 articles published with the participation of non-Iranian researchers, the number of non-Iranian collaborations was between 1 and 7 and the average number of authors with non-Iranian researchers (3.5 ± 1.57).
The gender distribution of the authors in the 123 articles with international collaboration showed that of the 406 authors, 145 were female (35.7%) and 261 (65.3%) male. The gender distribution of articles with purely Iranian authors was 1,984 (72.4%) male and 755 (28.6%) female.
The minimum and maximum number of male authors in collaborative articles varied between 0 and 7 authors (2.9 ± 1.4). The minimum and maximum number of female authors in collaborative articles varied between 0 and 3 authors (0.53 ± 0.71). The minimum and maximum number of male authors in non-contributing articles was 0 to 11 authors (3.1 ± 1.02) and the minimum and maximum number of female authors in non-contributing articles was 0 to 5 authors (1.8 ± 0.57). The T-test for comparing the mean number of male and female authors in each article with and without the collaboration of international researchers showed no significant difference.
The separation of articles based on the three fields of water and air pollution and solid waste management showed water pollution to have the highest number of international collaborations in writing scientific articles with a frequency of 235 authors. Of the total of 3,145 Iranian and international authors who participated in the writing of the 883 articles in the three fields of water and air pollution and solid waste management, 406 (12.9%) participated in the writing of 123 joint articles (Table 2).
Table 2
Frequency of authors by gender in articles with and without international collaborations 2008–2019
Fields of environmental health | Male | Female | Total |
Articles with international collaboration | Articles without international collaboration | Articles with international collaboration | Articles without international collaboration | Articles with international collaboration | Articles without international collaboration |
Water pollution | 174 | 1,206 | 88 | 426 | 235 | 1,632 |
Air pollution | 70 | 417 | 23 | 174 | 93 | 591 |
Solid waste management | 44 | 361 | 34 | 155 | 78 | 516 |
Total | 261 | 1,984 | 145 | 755 | 406 | 2,739 |
Iranian Researchers’ Collaboration With International Researchers
Among the 529 articles related to water pollution, 67 collaborative articles were written by 235 researchers from 20 countries. The largest contributors to research on water pollution were from the continent of Asia with 42, then came Africa and Europe with 14 and 11, respectively.
The highest collaborative rate in writing about water pollution came from India with 38 researchers collaborating on 12 articles, 20 Malaysian researchers collaborated on 10 articles and 17 Chinese on 7 articles.
Of the 196 articles related to air pollution, 93 authors contributed to 29 international articles. Of these 93 authors, 33 researchers were from 5 Asian countries and contributed to 15 articles. The highest number of collaborations in the writing of air pollution articles were from Indian researchers (5 articles and 12 authors), Turkey (4 articles and 6 authors) and Taiwan (3 articles and 9 authors).
Of the 158 articles on solid waste management, 27 were written with the participation of 78 authors from three continents, most of whom were from Asia with 18 articles. The evaluation of researcher collaboration from the perspective of countries showed that, despite 11 countries collaborating in waste management research, Indian researchers (with 16 articles and 35 authors), Egyptian researchers (2 articles and 8 researchers), and Chinese researchers (2 articles and 6 researchers) were the most collaborative with Iran.
VOSviewer software was used to map the co-authoring network of Iranian researchers with international researchers across continents and countries in all specialised articles on the three fields of environmental health issues (water and air pollution and solid waste management). Based on this software, a network was drawn in which the size of each node represents the number of articles shared by each country and continent with Iran, and the diameter of the link between the two nodes is proportional to the number of co-authored articles. Because of the collaboration of countries with Iran in this study, Iran was placed at the centre of the nodes with the largest number of articles. In this map, the continents and countries most closely associated with Iranian writers were geographically closer to Iran, i.e. Asia, Africa, and Europe (Fig. 2). In total, 27 countries collaborated with Iran in the writing of 123 articles, and the highest number of collaborations were from India, China, Malaysia and Turkey with 25, 15, 14 and 9 articles, respectively (Fig. 2).
A survey of 123 articles written by Iranian and international authors in the three fields of water and air pollution and solid waste management showed that the largest number of researchers were from India and China with 64 and 47, respectively. In total, 27 countries from 5 continents were involved in writing articles with Iran (Fig. 3). Among the articles reviewed, five were written in collaboration with more than two countries and four were published by researchers from three countries: Iran, Malaysia and Japan; Iran, South Korea and India; Iran, Ethiopia and Mexico; Iran, Egypt, Spain. One article was written between four countries: Iran, South Korea, China and India. The study of the authors' distribution by continent showed that of 406 authors, 284 were from 11 countries in Asia. Also, the largest number of 70 articles came from Asia. Researchers from Africa, Europe, the United States and Oceania published 22, 19, 11 and 1 articles with Iranian researchers, respectively (Fig. 3).