**5. Environmental effects of POPs**

POPs can travel long distances in the environment by air or in water so that they are found in ecosystems in which they have never been used and far from their source. Animals of the Canadian Arctic have significant levels of PCBs, organochlorine pesticides (like DDT), and metals, and this poses a health risk to the human population that relies on these animals as a food source. The long-range transport of POPs leads to global pollution (**Figure 2**) [13].

Degradation Pathways of Persistent Organic Pollutants (POPs) in the Environment http://dx.doi.org/10.5772/intechopen.79645 21

**Figure 2.** Transboundary movement of POPs. (Source: Ref. [13]).

**4.1. Effect on endocrine disruption**

20 Persistent Organic Pollutants

**4.2. Effect on the reproductive system**

triosis have been reported [9, 10].

circumference and chest circumference [12].

**5. Environmental effects of POPs**

Exogenous substance/mixture that alters the function(s) of the hormonal system and consequently causes adverse effects in an intact organism or its progeny or its subpopulation is called endocrine disruptors. The majority of POPs are known to disrupt the normal functioning of the endocrine system. Low-level exposure to POPs during critical developmental periods of the fetus, newborn, and child can have a lasting effect throughout its lifespan. A 2002 study [8] synthesizes data on endocrine disruption and health complications from exposure to POPs during critical developmental stages in an organism's lifespan. The study aimed to answer the question whether or not chronic, low-level exposure to POPs can have a health impact on the endocrine system and development of organisms from different species. The study found that exposure of POPs during a critical developmental time frame can produce a permanent change in the organism's path of development. Exposure of POPs during non-critical developmental time frames may not lead to detectable diseases and health complications later in their life. In wildlife, the critical development time frames are in utero, in ovo, and during reproductive periods. In humans, the critical development time frame is during fetal development [9].

The same study in 2002 with evidence of a link from POPs to endocrine disruption also linked low-dose exposure of POPs to reproductive health effects. The study stated that POP exposure can lead to negative health effects especially in the male reproductive system, such as decreased sperm quality and quantity, altered sex ratio, and early puberty onset. For females exposed to POPs, altered reproductive tissues and pregnancy outcomes as well as endome-

A Greek study in 2014 investigated the link between maternal weight gain during pregnancy exposure and PCB level in their newborn infants, their birth weight, gestational age, and head circumference. The lower the birth weight and head circumference of the infants was, the higher POPs levels during prenatal development had been, but only if mothers had either excessive or inadequate weight gain during pregnancy. No correlation between POP exposure and gestational age was found [11]. A 2013 case-control study conducted in 2009 in Indian mothers and their offspring showed prenatal exposure of three types of organochlorine pesticides (HCH, DDT and DDE) impaired the growth of the fetus, reduced the birth weight, head

POPs can travel long distances in the environment by air or in water so that they are found in ecosystems in which they have never been used and far from their source. Animals of the Canadian Arctic have significant levels of PCBs, organochlorine pesticides (like DDT), and metals, and this poses a health risk to the human population that relies on these animals as a food source. The long-range transport of POPs leads to global pollution (**Figure 2**) [13].

**4.3. Effect on gestational weight gain and newborn head circumference**

**Figure 3.** Transport and circulation of PCDDs/PCDFs and PCBs in the environment. (Source: Ref. [14]).

The slow decomposition of PCDDs/PCDFs and PCBs in the environment and the hazards they pose for living organisms make them large-scale environmental degraders, especially because their toxicity can be further enhanced by their ability to accumulate in the soil and sediments and their bioaccumulation and biomagnification within aquatic and land food chains (**Figure 3**) [14].
