Previous findings
Sudhakar et al. (2007) studied the loss of mass of synthetic
plastics in seawater due to (bio)degradation. To
this end, they immersed samples of HDPE, LDPE and PP
in the Bay of Bengal near Chennai Port (Port) and Fisheries
Survey of India (FSI) for a period of six months with a
monthly sample withdrawal. This study indicated maximum
losses of mass of 1.5-2.5% for LDPE, 0.5-0.8% for
HDPE and 0.5-0.6% for the PP after six months of exposure.
In studies of Albertsson & Karlsson (1990) it was
found that the LDPE buried in soil lost 3.5% of its mass
in 10 years. This low rate of decomposition is in accordance
with studies of Otake, Kobayashi, Asabe, Murakami,
& Ono (1995), in which it was found that 10 years is a relatively
short period of time for biodegradation of synthetic
polymers, such as polyethylene [3]. The same study reports
a mass reduction of 2.5% in LDPE and a decrease
in tensile strength of 24 to 20 MPa in 6 months in tropical
conditions. The formation of carbonyl groups was found
to help microorganisms in the process of degradation.
Note that under tropical conditions, higher levels of biodegradation
can probably be expected due to the higher
levels of temperature, oxygen and microorganisms