Most of the plastic bottles and caps that pollute the Pacific coasts of Latin American countries are of local origin, and are mainly produced by the multinational companies The Coca-Cola Company, Aje Group and PepsiCo. The countries most affected by these pollutants are those in Central America, probably due to high consumption of beverages in plastic containers, poor waste management and transport by ocean currents. On the island coasts, bottles of Asian origin are more abundant, probably dumped from ships and transported by currents.
These are some revealing findings of the first regional study to track plastic bottles (and caps) on beaches and coastal cities in 10 Latin American countries. Along more than 12,000 kilometres of Pacific coastline from Mexico to Chile — including islands such as Rapa Nui (Easter Island), the Galápagos and Robinson Crusoe — the study sampled a total of 92 mainland beaches, 15 island beaches and 38 human settlements.
The paper, published in the Journal of Cleaner Production, involves researchers Miquel Canals and Ostin Garcés-Ordóñez, from the Consolidated Research Group in Marine Geosciences of the Faculty of Earth Sciences of the University of Barcelona, who are also director and member, respectively, of the UB Chair on Sustainable Blue Economy, sponsored by the environmental consultancy Tecnoambiente.
The study, which covered Mexico, Guatemala, El Salvador, Nicaragua, Costa Rica, Panama, Colombia, Ecuador, Peru and Chile, relied heavily on citizen science, thanks to the involvement and collaboration of 1,000 volunteers and 200 local leaders from 74 social organizations.
Faced with the problem of plastic pollution, the study warns of the urgent need to strengthen local waste management and to implement regional actions to reduce the environmental impact of these products. Given that the most consumed products are single-serve and single-use bottles, it is recommended that the production of returnable and reusable packaging be encouraged by the companies that produce them.
Bottles carrying information
Plastic pollution is a problem that affects the entire planet. On the coasts, plastic bottles and caps are a major component of accumulated litter and it is therefore essential to identify where they come from in order to improve the management of this type of waste and prevent its environmental impacts.
Between 2023 and 2024, citizens and other participants collaborated with scientists to collect samples of plastic beverage containers and their caps as part of the most ambitious study to date on Latin America’s Pacific coast to determine the abundance, source and characteristics of these pollutants.
“In addition to the great value of citizen science, a particularly remarkable element of the work carried out is the intelligent use of the information contained in the bottles and their caps (labels, engravings) to obtain key information about the manufacturer, and the date and place of manufacture, among others,” says Miquel Canals, professor at the Department of Earth and Ocean Dynamics. “This allowed us to identify the sources of this contamination and the route taken by individual items until they reach the beach or town where they were collected.”
Soft drinks, energy drinks and water containers were the most common, reflecting regional trends in beverage consumption. Most of the bottles were single-serve bottles, which contributes to inadequate waste management and increased environmental impact. Single bottles, with and without caps, predominated in urban areas and on mainland beaches (54.9%), while bottles with caps were more common (73.4%) on island beaches.
Fifty-three percent of the beverage bottles and caps collected had visible dates, while 59% of the items with identifiable origin were from Latin American Pacific countries themselves. A total of 356 brands belonging to 253 companies were identified, the most frequent being The Coca-Cola Company, Aje Group and PepsiCo.
The oldest objects were a Powerade® bottle from 2001, collected on a mainland beach in Peru, and a Coca-Cola® bottle from 2002, found on a Chilean island.
In general, the predominant bottles were less than one year old, while the highest percentages of older bottles were found on island beaches in Chile and Ecuador, as well as on mainland beaches in Mexico, El Salvador and Costa Rica.
“These findings point to a spatial pattern in the age of the items: the most recent ones predominate in human settlements, while the oldest ones are found on beaches, especially on the beaches of oceanic islands,” says researcher Ostin Garcés-Ordóñez, lead author of the study and member of the UB’s Consolidated Research Group in Marine Geosciences and the University of La Guajira (Colombia).
Bottles of local origin, but also Asian, European and North American
Regarding the origin of the bottles, the majority of those analysed with an identifiable origin (59.2%) came from Pacific countries of Latin America. Smaller proportions came from Asia (1.8%), North America (0.3%) and Europe (0.04%). In 38.7% of cases, the origin could not be identified.
“On the mainland beaches of Mexico, Guatemala and the southern countries — Colombia, Ecuador, Peru and Chile — most of the bottles came from the same country. In contrast, in the Central American countries — El Salvador, Nicaragua, Costa Rica and Panama — the percentages of locally sourced items were significantly lower, with those of external origin predominating,” the authors note.
On the island beaches, 42.4% of the bottles came from Latin American countries, but also had the highest percentage of items of Asian origin, and smaller proportions of European and North American origin. Panama showed the greatest diversity of origins, with items from at least six Latin American, Asian and North American countries. The island beaches of Rapa Nui and the Galápagos had very low percentages of locally sourced bottles and high proportions of products from Asia.
“The distribution of bottle origins is not random, but geographically structured, with a predominance of specific countries of origin in specific environments and sub-regions, and also in specific countries, of course,” the authors say. “This trend would reflect the consumption habits, waste management practices (where they exist) and oceanographic transport processes that influence the distribution of these plastic pollutants.”
“The study also identified the presence of epibionts — organisms that live on other living things or surfaces, such as those on plastic bottles and caps, and which are indicators of the exposure and residence times of objects in the marine environment — in 8.8% of the bottles found on beaches on average, a proportion that was higher on mainland beaches in Central American countries. This pattern reinforces the idea of plastic bottles and caps arriving at these sites via marine currents.
Towards greater individual, social and corporate responsibility
Raising public awareness about respect for the environment, promoting the use of reusable packaging and strengthening the corporate social responsibility of producers — together with international actions such as the UN Global Plastic Treaty — are essential strategies to reduce plastic pollution and protect coastal ecosystems. These actions could be replicated in other regions of the world to minimise the human footprint on natural environments and improve the healthiness of urban environments.
“In the future, we want to analyse the impact of seasonal climatic variations, river inputs and tourist activity on the dynamics of plastic bottle and cap pollution on coasts and in coastal cities. Oceanographic modelling could also be integrated to track the transport trajectories of plastic litter in the ocean and thus identify distant sources of pollution,” conclude Miquel Canals and Ostin Garcés-Ordóñez.