Harold Tso was born to Franklin Tso, Sr. and Sarah Goodluck Tso in Fort Defiance, AZ. He was the 1st of 7 children. His two sisters and youngest brother survive him. While a baby, his family moved to Shiprock, NM. He attended elementary school in Shiprock and middle and high school in Farmington, NM. He excelled at Farmington High School and earned a place at Cavin College in Grand Rapids, MI. He graduated with a Bachelor of Science degree in Chemistry and Biology.

He returned to Farmington and worked for the New Mexico Department of Health as a chemist Between two stints with the Department of Health, Harold worked on a graduate degree in radiation biology at the Colorado State University, married Mary Thomas, and they welcomed a few sons. After a few years, the young family moved to Santa Fe, NM, where they welcomed a daughter.

In Santa Fe, Harold worked for Eberline Instrument Corporation as a chemist, the first of 3 stints with the company. In all, Harold worked 18 years at Eberline.

From 1965 to 1968, Harold supervised the radiochemical analysis of water and natural gas samples for the state of New Mexico Department of Public health.

From 1968 to 1974. He was the chief chemist for Eberline instrument, corporation, in Santa Fe, New Mexico. he performed and supervised radiochemical analysis of environmental samples such as air, water, soil, silt, vegetation, vegetables, small animals, and fish as well as bioassay samples. Such samples were analyzed for such radionuclides as tritium carbon 14, cobalt 60, cesium-134,137, iodine 125, iodine 129, iodine 131, radium, thorium, uranium, Neptunium, plutonium, and americium isotopes. The samples were from sites or individuals who worked with nuclear reactor operations, reprocessed nuclear fuel rods, or prepared nuclear fuel rods.

Clients represented nuclear, regulatory agencies from state government federal agencies, and from private corporations. The samples were analyzed for regulatory or monitoring purposes. During his tenure analytical results of samples from several sites confirmed estimated projections of radiological experts and enabled regulatory or monitoring agencies to perform their mandated responsibilities.

Harold was employed from 1974 to 1985 by the Navajo tribe consecutively as executive Director of the Navajo Tribal environmental protection commission, Navajo Energy and resource development, and Navajo division of resources.

He established a tribal environmental office with the staff which monitored and evaluated environmental impacts of resource development activities, such as mining, oil, gas, sand & gravel operations, on Navajo lands and its residents.

The staff evaluated, environmental impact statements or assessments, and proposed mining plans. He or his staff met with appropriate federal or corporate officials to convey or mitigate Navajo concerns. He submitted formal testimony to appropriate US congressman, or their committees on abandoned uranium Mills, United nuclear uranium spill, US surface mining control and reclamation act, and the US Clean Air Act.

During his tenure with the Navajo Tribe, Harold served on the US national commission on air quality. He was appointed by US President Jimmy Carter. He also served on the science and technical assessment committee for the US environmental protection agency.

For the energy and resource development Harold served Navajo tribal Chairman Peterson Zah, providing leadership for the Navajo minerals negotiating committee. The committee effected new lease agreements with Energy and mineral companies that resulted in an increase in tribal revenues.

For the research division, Harold provided leadership and supervise several departments whose responsibilities included land, cultural resources, Forestry, Fish and wildlife, and minerals.

Harold was employed by Jacob engineering group incorporated from 1988 to 1993 as a chemist. He assisted for working groups by evaluating water, quality data and supervised the hydrology laboratory for the hydrology group. He participated in annual team audits of analytical laboratories and updated standard operating procedures for the quality assurance group. He prepared scopes of work for the chemical analysis of water samples and evaluated bid proposals submitted by analytical laboratories for the contracts office group. Harold evaluated onsite and offsite, environmental data from previous studies, and investigated the applicability of Federal and State environmental laws and regulations for the jack pile project group. From 1993 to 2002 Harold was again employed by Eberline services as chief chemist. He was laid off in 2002 and chose retirement.