**Abstract**

Microplastics (MP) refer to all plastic particles that are less than 5 mm in size. Over the past decades, several studies have highlighted the impact of microplastics (MP) on living organisms. In addition to being pollutants themselves, these synthetic polymers also act as vectors for the transport of various types of chemicals in natural ecosystems. MP has been ubiquitously detected in a wide range of shapes, polymers, sizes and concentrations in marine water, freshwater, agroecosystems, atmospheric, food and water environments. Drinking water, biota, and other remote places. According to the World Bank, over 80% of the world's marine litter is plastic and the concentration of litter on Caribbean beaches is often high, with a high presence of single-use plastics and food containers. In its work, the World Health Organization (WHO) suggests an in-depth assessment of microplastics present in the environment and their potential consequences on human health, following the publication of an analysis of the state of research on microplastics in drinking water. It also calls for reducing plastic pollution to protect the environment and reduce human exposure. In Haiti, the bay of Port-au-Prince is the natural receptacle of all the urban effluents generated by human activities in the Metropolitan Zone. This urban wastewater carries household waste, sludge from pit latrines and sewage, industrial wastewater which largely contributes to the pollution of the bay. Furthermore, 1,673,750 tonnes per year of household waste, including 93,730 tonnes of plastic waste, are not collected. What are the environmental dangers represented by the MP contained in those wastes for living organisms in exposed tropical ecosystems? The purpose of this paper is: (i) to do a bibliographical review of the physical and chemical properties, as well as the toxicological profile of MP, (ii) to identify the environmental hazards associated with MP contained in urban waste in the metropolitan area of Port-au-Prince.

**Keywords:** microplastics, wastes, physical and chemical characteristics, natural ecosystems, fate, environmental hazards

### **1. Introduction**

Synthetic polymers appeared at the end of the nineteenth century around the 1860s, but it was not until after WorldWar II that the "rise of plastics" really began [1]. Plastic has become one of the most ubiquitous materials since its inception as a phenol-formaldehyde resin (i.e., bakelite) [2]. Basically, plastic was designed to improve the conditions of human life, but today it is becoming a real environmental concern [1].

Nowadays, plastic is ubiquitous in all environmental compartments (air, water, and soil) [3]. Simonneau et al., [4] report that rain and snow contain a significant number of MP, invisible to the naked eye and less than 5 mm in size. The presence of MP in soil ecosystems has been detected [5, 6]. Scientific literature reports the environmental occurrence of MP in surface waters [7], coastal sediments [8], beach sands [9], freshwater sediments [10], and deep-sea environments [11]. Indeed, the intensive exploitation of plastic associated with poor performance of waste management systems, including end-of-life collection and capture, have resulted in a massive accumulation of plastic waste in the environment [12]. The release of plastic materials into the environment is recognized as an important pollution related issue [13–15].

The proliferation of MP in the environment causes serious pollution all over the world [16]. According to their characteristics, namely, synthetic materials with a high content of polymers, solid particles, less than 5 mm, insoluble in water, and not degradable, they are easily introduced into the environment and persist there due to their low solubility [17]. Food chains are subject to significant pollution from the release of hydrophobic organic chemicals [18–22]. Being present in different aquatic ecosystems (surface water, oceans, estuarine waters, etc.), organisms are directly or indirectly exposed to microplatiscs [17]. Scientific literature reports negative impacts of microplastics on benthic organisms [23, 24]. The toxic effects of these pollutants have been studied on the feeding habits, growth and reproductive systems of several aquatic species [25–29]. Human beings are therefore exposed through the consumption of seafood, fish and crustaceans [30].

The purpose of this paper is: (i) to do a bibliographical review of the physical and chemical properties, as well as the toxicological profile of MP, (ii) to identify the environmental hazards associated with MP contained in urban waste in the metropolitan area of Port-au-Prince.

### **2. Methodology**

Scientific and technical information from several world-wide documentation databases was used. Academic social networks, scientific databases such as Google Scholar, PubMed, academia.edu, researchgate.net, academic presses (springer.com, sciendirect.com, Wiley Online Library, ACS Publications, etc.) were consulted in this way as electronic data available on the sites of certain research universities. The search equations launched on the various sites consulted were implemented from the crossing of the following keywords: "Microplastics", "Microplastics (and) definition", "Microplastics (and) plastics", "Microplastics (and) thermodynamics", "Microplastics (and) Epidemiology", "Microplastics (and) physical and chemical properties", "Toxicological profile of microplastics", "Microplastics (and) Human health effects" , "Microplastics (and) Environment" , "Microplastics (and)) partition coefficient" , "Microplastics (and) Haiti", "Haiti (and) solid waste" , "Fate and Microplastics" , "Microplastics (and) Ocean" , etc.

The results obtained have been the subject of a critical examination. Each article read, referred the authors of this study for the reading of another article cited in the list of his references. We considered articles that were published from 2005 to 2021. The number of times cited (citations analysis).

*Microplastics and Environmental Health: Assessing Environmental Hazards in Haiti DOI: http://dx.doi.org/10.5772/intechopen.98371*
