Three units of cathode ray tubes (CRTs) or picture tubes of old-fashioned televisions have been retrieved along a sidewalk in Manila which are potentially hazardous to health and the environment as they contain hazardous chemicals such as lead and mercury, an environmental health organization said on Tuesday.

EcoWaste Coalition expressed concern over the indiscriminate disposal of end-of-life CRTs of old television and computer sets as these will cause the release of chemical substances into the environment. 

"Exposure to these substances in CRTs is detrimental to human health. Like other electronic waste, CRTs require sound management to avoid toxic pollution," EcoWaste Coalitions' chemical safety campaigner Thony Dizon said.

Aside from lead and mercury, the other chemicals of concern found in CRTs are antimony, arsenic, barium, beryllium, cadmium, nickel phosphor, and rare earth metals, the EcoWaste Coalition said.

Lead, which is found on the CRT glass panels to improve optical quality and to act as a shield against radiation, is listed by the World Health Organization (WHO) as among the "ten chemicals of major public health concern" along with arsenic, cadmium, and mercury.

According to the WHO, lead "is a cumulative toxicant that affects multiple body systems, including the neurologic, hematologic, gastrointestinal, cardiovascular, and renal systems."

E-Waste campaigner Roxanne Figueroa also noted that the plastic casings of old TVs and computers may contain highly toxic flame retardant chemicals, such as polybrominated diphenyl ethers (PBDEs), which are banned globally under the Stockholm Convention on Persistent Organic Pollutants (POPs) to which the Philippines is a party.

The Stockholm Convention on POPs is a global treaty to protect human health and the environment from the adverse effects of POPs.

Adopted in 2001, the Convention entered into force in 2004, the same year it was ratified by the Philippines. It requires the parties to take measures to eliminate or reduce the release of POPs into the environment.

"PBDEs, which are commonly used in consumer electronics such as TVs and computers to reduce flammability, are known endocrine disrupting chemicals that can interfere with thyroid function, reproduction, and neurological development," Figueroa said.

"To protect the health of the people and the ecosystems, the government, with the participation of various stakeholders, is promoting the environmentally sound management of PBDEs in e-waste," she said.

The government, led by the Department of Environment and Natural Resources, is currently implementing the "Safe PCB and E-Waste Management Project" funded by the Global Environment Facility and the United Nations Industrial Development Organization.

PCBs refer to polychlorinated biphenyls, one of the original 12 POPs which are targeted for elimination under the Stockholm Convention. 

The "Safe PCB and E-Waste Management Project" is a 60-month project implemented in December, 2016.

It targets the environmentally-sound disposal of 600 metric tons of PCB-contaminated oil and equipment, and 1.15 tons of PBDEs as global environmental benefits.