Global pollution by plastics derived from petroleum has fostered the development of carbon–neutral, biodegradable bioplastics synthesized from renewable resources such as modern biomass, yet knowledge on the impact of bioplastics on ecosystems is limited. Here we review the polylactic acid plastic with focus on synthesis, biodegradability tuning, environmental conversion to microplastics, and impact on microbes, algae, phytoplankton, zooplankton, annelids, mollusk and fish. Polylactic acid is a low weight semi-crystalline bioplastic used in agriculture, medicine, packaging and textile. Polylactic acid is one of the most widely used biopolymers, accounting for 33% of all bioplastics produced in 2021. Although biodegradable in vivo, polylactic acid is not completely degradable under natural environmental conditions, notably under aquatic conditions. Polylactic acid disintegrates into microplastics faster than petroleum-based plastics and may pose severe threats to the exposed biota.

Data on environmental contamination of the parasites of zoonotic importance is scarce in Pakistan. Soil contamination with feces of dogs hide infective stages of the parasite represents a health-risk to humans. This study was aimed to assess the eggs of gastrointestinal parasites of stray dogs and household dogs in lower Dir district, Pakistan with special consideration to those that can be spread to humans. One hundred and fifty two stool specimens from (stray dogs=90 and household dogs=62) were collected. The helminth eggs were processed by direct smear method and centrifugation techniques and identified by microscopic examination. Of the total examined dogs 26.8% (n=41 /152) were found to be infected with one or more intestinal parasites. The intestinal helminths detected were Dipylidium caninum (n =18, 11.8%), followed by Toxocara canis (n =16, 10.5%), Taenia spp., (n=10, 6.57%) Ancylostoma caninum (n=6, 3.94), Toxascaris spp., Capillaria spp., and Trichuris vulpis (n=2, 1.31% each) in order of their prevalence. Pattern of infection revealed that 27 (65.8%) dogs have single, 13(31.7%) double and 1(2.43%) triple infection. The stray dogs were highly infected 34.4% (n=31) than house hold dogs 16.1% (n=10). The prevalence of infection with intestinal parasites was significantly different among these two groups (p = 0.0097). This study highlight a severe environmental contamination by frequent parasitic stages infectious to humans. There is a higher risk of zoonotic transmission from dogs which indicate an immediate need for the controlling of these parasites and educating the public to take wise action relating to the parasites and pets.

Marine environments are polluted by plastics debris originating from land sources and from plastics used in maritime sectors such as fisheries and aquaculture, shipping, and offshore energy infrastructures. Here we review marine plastic pollution with emphasis on plastic sources, socioeconomic impact on marine industries, regulations, circular economy, and the use of bioplastics to mitigate pollution. Marine pollution sources include fisheries, aquaculture, shipping, boat industries, tourism, offshore energy plants, and artificial reefs. Fisheries and aquaculture use about 2.1 million tons of plastic annually and contribute approximately 18% of marine-based plastic pollution, primarily through lost, abandoned, or discarded fishing gear. Maritime transport contributes to plastic pollution through waste discharge, accidental container losses, and emissions from paint coatings. Marine coatings alone account for approximately 3.7% of primary microplastics entering the ocean. Coastal and marine tourism, and cruise ships generate plastic pollution via single-use plastic waste and greywater release. Artificial reefs generate plastic pollution via weathering of underwater structures. The use of bioplastics in marine and coastal tourism is increasing, particularly for single-use packaging. Bioplastics are being tested in prototype gear and nets. Nonetheless, there are limitations in the use of bioplastics because some of them are not or hardly biodegradable, some of them are not biobased, and bioplastic-derived microplastics have been detected in marine environments and biota with ecotoxicological effects comparable to those of conventional microplastics.